Present Indicative:......he is......he comes
Present Subjunctive:...he be.... he come
Past Indicative: .........he was ..he came
Past Subjunctive:.......he were. he came
Not a teacher
Yes, some say that there are two tenses in English. I am pretty much sure that this concept is correct but not useful for majority.
Were he a talented musician I would invite him to play.
Be he a talented musician I will invite him to play.
1) I can say only about my personal experience as for this concept of two tenses in English. I have never seen good results achieved by average students using this concept. I still must admit that only Russian speaking students are implied. May be for some students it is a useful thing.
2) Be It Right Or Wrong.
Be that as it may.
If you wish to know if those two are acceptable English, the answer is 'yes', though the first would very rarely be met in BrE. They are not, however, normally acceptable on their own; each is part of a longer utterance.