ahinoa

Sure.  You must travel BEFORE the visa expires.  How long before, does not matter.

Info (snapshots, etc) on the times you were together and info about your SO (what kind of place does he/she have, where you will be living, what kind of work does he/she do, details like that) will go a lot further than chat logs. 

Age alone is not a reason for refusal. However, if the age gap is unusual in your culture, then it can be used as one factor - among multiple - in consideration that the marriage is not bona fide.

Yes, it could have an impact. How long you've known each other, how many time you've visited, for how long. All those things will be taken into consideration. I'd suggest being prepared to be asked about it, because I'd imagine it would come up. 

it took 5 buisness days for us to get case complete/ para nostros tardaron 5 dias despues que mandamos el documento que nos pideron.