Paulnew
1: Yes, you can, but if you understand things like variables, if then else statements, for loops and arrays, it will make things easier and allow you to make more complex games. You don't need to know those things for your first few games though.
2: Sure you can. If you do happen to need maths at some point, just ask on the forums and someone will more than likely help you out.
3: Construct 2 uses NW.js to create games that run on windows with an .exe
4: I'd suggest looking into the tutorials on here first, along with the included examples and the manual. Scirra also post on Facebook about useful videos and recently posted about this free e-book about making Construct 2 games.
5: Yes, you an make an RPG. Lot's of different types of games have been made with Construct 2 - RPGs, RTS, shmups, platformers, puzzlers, etc. Check some of them out here
Don't forget to try the free version of Construct 2 first to see how it works.