> realizing it was never going to work how I liked.
> You can't have it all with the mouse no matter your settings
> so I went back to just using the cursor to move things around.
These tools (vim, tmux, etc.) work great for mouseless setups. If you can get comfortable with a 100% keyboard control paradigm, it might work for you. I realize this might not be what you want, but if the statement "spend less time moving your hand between keyboard and mouse" resonates, it's worth revisiting.
My biggest problem with "mouseless tmux" was copy-paste. How do you deal with that?
I had the very same problem. Especially, I could not jump to the string I wanted to copy. I wrote a tmux plugin for it https://github.com/schasse/tmux-jump
Maybe it helps you too. Works great with https://github.com/tmux-plugins/tmux-yank