Currently we have is grammatically correct.
currently exists
That is the correct spelling of the adverb "currently" (at the present time).
The correct spelling is "currently"
'She does not have her book' is grammatically correct.
He, you and I is not grammatically correct. The proper way to say this is you, him and I.
Usually you would say that you were at the office, but saying that you were in the office is grammatically correct as well (as long as you are technically in the office building). "I am in office" without the word "the" is only correct if you are currently holding a position which expires (like President or Chair).
Yes, 'for free', is grammatically correct.
Yes it is a grammatically correct
"Not like that" can be grammatically correct, depending on the context.
Yes! That is grammatically correct!
Yes, soonest is correct grammatically.
This is not grammatically correct. The correct form is 'you do not know', or the abbreviated 'you don't know'.