Often it's reported that a larger and/or brighter crosshair helps. Maybe try an overlay with a large neon pink crosshair or a piece of clear tape with a big dot of marker on it sometime? I get it's probably not a problem that you are interested in putting time into solving any more though.
As I recall, the 'campaign' gets impossible to do with two players because of the inability to look up enough stuff in parallel. There are mods and custom bombs though.
Your description of vendor lock-in is obviously solvable by developers making a competing UI and workflow similar to the most popular software, and enabling new features under another menu. That said, there is obviously minimal interest in doing so.
This is UI. UI is not vendor lock-in. Lock-in costs users money to break out of, not developers.
Sometimes I just like killing rooms of enemies by walking around. I like Warframe for that - specifically I have a Gyre build that goes pretty hard even through steel path. Nice brain off time.
I like mentoring, but my skill set is deep and narrow. DM me and we'll see if they overlap and if I can match the time commitment that you are looking for, if you are interested. No fee.
There are zipper "fitted" sheets that avoid this problem