I wanted to enquire the following:
1) I got engaged last year, and got into mutah with her for a period of 1 year, ( i got my mutah recited on 15th april which was 2nd ramadhan) , wanted to ask do i need to follow the islamic dates or english dates while renewing( so do i have to renew again on 2nd ramadhan or 15th April?)

2) During my Muta/Nikah, my wife can ask me for Mahr, which can sometimes be something non monetary as well, if i get a mahr condition which is a future scenario( eg, to pursue further studies after nikah) for which we both have mutually agreed to comply, but however due to some scenarios/circumstances, the above mahr condition can not be fulfiled, does it then invalidate the Mutah/nikah?

1) You can follow the same calendar according to that you had done your Mut'a first time.

If a man has a temporary wife whose ʿiddah has not yet finished, he can contract a permanent marriage with her or marry her again in a temporary marriage. However, if the period of the temporary marriage has not yet finished and he contracts a permanent marriage, the marriage contract is invalid unless he first gives her the remaining period and then contracts the permanent marriage.

So you can renew you Mut'a period for further dates once the first time slot has been over.

2) If her demand is as a dowry of Mut'a and you have agreed on it then you will be entitled to pay it to her.