ConsolePort introduces a snap-cursor thing for menu/bag navigation where use a D-Pad to move a selector around bags and menus.
For things where you have to click (looting, fishing, ground targeting, etc) you can use a button to unlock the cursor and use the right thumbstick to move it around. Mine has R3 bound to unlock the cursor, and then L3/R3 act as right and left click. Since I have an Elite controller, I have paddles bound to R3 and L3 and use those to get into and out of mouse mode fairly quickly.
You can bind things to act as modifiers--I have LT and RT as my modifiers, and am running something based on what's shown in
this video. I have some non-skill things bound to buttons without a trigger held down (jump, targeting, etc), then 10 buttons (D-Pad, A/B/X/Y, LB, RB) with three different modifiers (LT, RT, LT+RT) available. Post-7.0, it's more than enough space for everything I've tried (even Druid, since bar 1 remaps with form shifts, all manages to fit). There's also a wheel you can lock things to for stuff you might want to access out of combat, and a raid cursor you can use to target party members although I've yet to get that feeling fluid enough to try healing.
The only thing I still need to figure out is how to change what the Extra Action Button and vehicle buttons bind to. The guy who makes ConsolePort has a hotbar replacement plugin I was using for a while that this all works with, but 7.0 broke it and I got hooked on the customizability Bartender had.