I'm almost done with this chapter but have a couple more questions.

Prepositions governing the instrumental case are covered. I want to make sure of the pronunciation of some of them. Would над, перед, под all be pronounced with a final /t/ but as a /d/ before another word, as in над этим диваном, под столом, перед лекцией?

Can someone help on this translation?
--Try (do your best) to do this well.
--All right, I will

--Старайся это хорошо сделать. (should this be сделать or делать?)
--Ладно. Я стараюсь. (perfective here?)

Thanks,
Z