Yes, the idea is about creating groups of contributors.

But it's even not about "trustworthed" or "untrustworthed" contributors.
The option "only native speakers sentences" is already exists, and it works well.
But personally for me nativeness is not so important, cause almost all people I interact in English aren't natives, and I consider English as a kind of international language (of course, I talk about advanced level contributors, not about beginners, which contaminate the corpus with weird and grammatical incorrect sentences). For Italian, Guybrush 88 makes a good job to keep the corpus clean and check and tag non-native sentences, so they can be considered trustworthed enough in my opinion.

There is another issue.
Firstly, many languages are spoken in more than one country. So, the ideal case would be if each sentence is marked with tags which dialect is it (if the sentence fits for several dialects, there should be several tags). But I think, it's impossible for now.
So, as I try to stick British English rules in spelling, vocabulary and pronunciation, I would like at least to have a list of BrE speakers.
Secondly, my personal preference is translating sentences, that express some thouths and feelings, tell some interesting facts, or just not trivial. Translating those phrases is much more fun, but not all the contributors create something like that.

I tried to describe the whole idea and my personal preferences, of course, every member could use that feature for their own purpose. The main thing, those lists should be visible only to their owners, and serve for their commodity, and if someone include you into their "white" or "black" list it shouldn't impact on your rating or "trustworthness".

I suggest to make it possible for every user to create their own private lists of contributors and display the sentences, added only by the contributors from the certain list (now we can only browse the sentences, added by one single contributor, but not by the group of contributors). For example, "Native British English contributors", "The German contributors, I like the most", and so on. Also it would be possible to display all the sentences in the language, excluding those, added by contributors from the certain "black" list (like "Chinese contributors, which style I don't like"). I suppose those lists only for private personal usage, so it's not any kinds of ratings, but the feature for user's commodity.

If a person has an email notification enabled, they often appear even after having been absend for a few month, if you comment their sentences. If the option is disabled,that's unlikely they will appear.

There is. If a person leave their homeland as a child, and not master their mother tongue anymore, but only use it for talking to their parents, his or her vocabulary remains rather limited and he or she tends to use unnatural phrases, due to a strong impact of the second language. But he or she is still a native speaker. That's the case of "native speaker with low level".

+1
All the sentences, owned by inactive users should be released. Else there is no chance to make them trustworthed sooner or later.

Just native? In that case it should be "native monolingual speaker".
For bilingual people the concept of a "native language" might be very vague, and some of them actually tend to use cultural or political reasons, chosing their native languages. So, if we don't want those battles here we'd better be ruled by the criteria of actual language skills and give corpus maintainers the right to decrise the level of those fake "natives", if their contribution is not good enough for this level.

I don't know what do you mean as "native level". If you're a native, it doesn't mean you never make any mistakes either. Do you mean "near native level"?

For some people it's different to determine their "native language", for example if they moved from their homeland in the early age. But it's always possible to say, if your contribution sounds good and natural or not. I think, most learners interested about your professionality in the language, not about if it's your actual mother tongue or not.

Do you mean, all you write in English can't be distinguished from anything that a native write in English by another native?

There is also another problem. Those people, who haven't come on the site since the possibility to indicate one's native language appeared, and they haven't set it, not appear like natives, even if they wrote in their profiles they were.

That's the point. We should estimate contribution, not contributors. Of course, while we don't have a reliable evaluation system, trustworthiness of authors is the main way to be more or less sure that a certain sentence is OK. But in the long-term outlook separation between "native" and "non-native" owned sentences isn't a good idea.

I realized, i have a different approach for tagging OK and adding sentences into my personal collection.
For tagging OK it's enought to ask myself "Can I hear the same sentence from people in my area, or on TV, radio, or read it in a book or a paper?" If yes, and it's grammatically correct above all, I would like to tag it OK, cause I can be sure, it's not worse than an average sentence created by a native Russian speaker, so there is no need to discriminate it.
But in my personal collection I would like to see something that I could recommend other people to remember. So, even a significant part of native speakers' contribution is not fit, if it sounds rather clumsy or seems like taken out the context.

If an author change their sentence, all the evaluations of the sentence will be kept?

Personally I don't see any difference, if I check my own sentence a few days or more after it had been written, or someone's else sentence. I even don't always can remember, that the sentence, I see as random, was written by me.

It has sence, if there will be several categories of sentences, like:

1) Standard sentences (the most valuable thing for most learners, I think). They are both grammatically correct according contemporary grammar rules of at least one of language varietes (like British or American English) and sound natural and not clamsy for almost all native speakers of those language variety, actively used by them (in collocuial or/and bookish speach) and understandable for almost all educated natives, regardless their age or location.
A sentence would get into this category, if, for example, 3 high-level speakers consider it like that. Actually, there should be only doubtless sentences there, doubtfull ones should not be included.
2) Sentences with curse words. I believe it should be a special category, cause some people strongly dislike that part of languages, so they could not be exposed by it.
3) Common mistakes. (tagged with "popular language" in the Russian corpus). These are sentences, frequently used by native speakers, but they are not considered as "correct" by current grammatical rules, so they are not recommended for using for school or university exams, in compositions, etc.
4) Slang sentences, which are mainly used only by people of some generation or subculture, and often are not understandable for others.
5) Dialect sentences, that contain dialect words or grammar forms, which are used only in some regions and seem odd or not understandable for people from other regions.
6) Archaic sentence, which contain archaic words, grammar, spelling or sintaxis, that is not correct according contemporary grammar rules, or just sounds archaic for most natives.
7) Non-standart sentences, which were intentionally created to be odd, absurd or peculiar, or grammatically correct sentences, there is no consensus in the corpus about if they are "natural" or "odd", so they are not fit for "standard" category. So, if the author wish to stay a sentence "as is" he or she could just mark it like "non-standart".
8) Rest sentences (bad orphan sentences, bad sentences created by non-native speakers, literal translations, just doudtful sentences which authors are not active now, and all the rest that should be change or deleted sooner or later should get in this category.).

It's disputable, how a sentence can get into one or another category. If someone's interested, I'll write some suggestions later.

Создайте пожалуйста список ваших предложений, которые нужно перевести на русский, и добавляйте туда все, что бы вы хотели, чтобы вам перевели, а ссылку на него поместите сюда. Можно также мне в личных сообщениях послать ее, чтобы было проще найти.

I agree, it's a big chance to link or unlink something by mistake now.

Yes, I know, but it's not their turn to celebrate it right now, so it's more likely, they are currently in Tatoeba :)

Sorry, Western, not Eastern

Sorry, Western, not Eastern.

*Eastern
Thanks :)
Happy New Year :)

It seems now there are mainly people from countries, that not celebrate New Year, or Tastern hemisphere here :)