If you have gear grinding, you may need any combination of a new clutch, new gears, and/or a fluid flush. Start with a proper fluid flush. If it doesnt help then the tranny needs to be dropped & opened to see what the issue is. Research all of this because its covered regularly, including a thread all about the tranny fluid flush itself.
Those are clearly aftermarker fenders which are notorious for fitment issues. Take your front end apart, inspect all the brackets, and realign each piece.
A 96-00 front end WILL fit as its been done before, so research it as it would require alot of work. Theres no sense in repeating whats already been covered.
An integra AC control will not fit without a complete custom job for fitment and wiring. Its just not worth the aggravation and cost.
I dont know what you mean by "rear center console" for AC controls, but double din installs have been done with slight modification whilevrelocating the AC controls to a lower din spot. Again, its been covered so look it up.
All your feasible questions have been covered many times on this forum and others so please get familiar with the search function. The point of all forums is to have one place to share and store helpful info for future referencing, not having people look it up for you. Good luck.