So I'm finally fed up after years of dealing with this problem and looking for how I can get this fixed and, approx. how much it will cost...

Here is what I've been dealing with (all sort of started around the same time years ago) on my 2009 Honda Fit (5 sp MT) - I am the original owner.

1.) Car will randomly "lock" itself again and again for about 2 min or so when I either start driving or after locking my car, usually in warmer weather.
2.) My back windows (both of them) will not open at all. They have not gotten wet, I've never had smokers in my car either. Front windows work ok.
3.) VERY, VERY difficult to unlock all doors (not just driver side) with my key fob.
4.) Easy to trigger car alarm when locking car with fob - very annoying.

I replaced my key fob and the same issues still persist so I know it's not the fob.

This is clearly an electronic issue with the system but I have no idea how to get this fixed. Has anyone dealt with this? If I knew what the issue was, I could go to the dealer and say "please do x y z" rather than pay for hundreds for them not to know what to do.