Spent too much time wonking a tmux config only realizing it was never going to work how I liked. You can't have it all with the mouse no matter your settings, there will always be a compromise. It also doesn't help that no one cites the version of tmux they wrote their configs for, nor that the configs are not backwards compatible with all versions of tmux for all settings.
It's really clunky, but I went from tmux to just opening new shell windows as needed. I need to be able to resize and scroll, selecting text and copy behavior should be exactly like mac os. Even used a tiling window manager with it for a bit, but it felt pretty restrictive so I went back to just using the cursor to move things around.
Yes, the mouse situation in tmux is catastrophic.
As much as I love tmux, I wonder what would it take that the program respects the usual copy-paste conventions like all the rest of X programs. You need to do two things, that are apparently impossible when tmux has "mouse enabled":
1. select some text in your xterm so that it gets copied
2. middle click on the xterm and your copied text (possibly from other window, web browser, whatever) gets pasted at the cursor position
This is really simple and sane behavior but it's completely impossible to achieve with the current version of tmux. I have spend much more time that I am willing to admit seriously trying to do that.