Yes, it is perfectly correct. 'If you were a mayor, you would be in control of a town council.'
To refer to the mayor of a specific place, for example your own town, you would omit 'a' or replace it by 'the':
'If you were (the) mayor, you would be able to change the transport policy.'
Yes, that is correct grammar.
Yes, 'you were correct' is perfect grammar. An example sentence: You were correct when you said that a tomato is a fruit.
This should say, The next stop will be somewhere in Vasayas, then it will be correct grammar. Written as it is it is not on correct grammar.
No, it is not correct
No, "Is was able to confirmed" is not correct grammar. The correct phrase would be "It was able to be confirmed."
Yes
Absolutely.
No, The correct grammar for this sentence would be, "He finished doing his homework."
It is not correct to say "they has studied". The correct way is to say "they have studied." There are many different places that a person can check grammar questions such as English grammar websites.
Yes, it is correct to say out of compliance with. It means out of help with in English grammar.
Correct grammar is Bob and I but most people use causal grammer and you and Bob is OK.
Sure.