Is there anyway I can change my username?

Is there a how to guide? I would like to tune all cars for realistic handling.

how does project realism work?

Is there a fully downloadable version that works with windows 10?

I was thinking about remodeling some buildings in SF and also re texturing most of the city, how can I do this??

Also is there a way to update the handeling model? I want it to feel like driving in GTAV

Thanks!