Paper with editor for longer than two and a half months I have submitted a paper to a journal 2 and a half months ago. Its status remains "With editor". From your experience, is this normal? If not, how should I deal with that?
One of my papers took well over two years to get published, thanks mostly to two review periods lasting around 10 months (IIRC).  So 2 1/2 months is not that outlandish.

But it does not hurt to ask politely about the status of your paper!  It may be well down on someone's list of things to do, and a polite reminder that you are interested in its fate may be all that's needed to bump it up near the top.  Presumably, if you ask, the editor will give some indication as to approximately when reviews might be ready, and then you'll know when to send another polite reminder if nothing has happened.