I didn't notice you were in the LumaFX forum and not the LumaFusion forum, and I think probably Dave didn't either (great minds are cracked in the same way).
Some of these features are available in LumaFusion, for instance, you can put a clip on the timeline and cut it up and delete parts as much as you like and trim. You can ripple tap on a video/audio clip and separate the audio onto a different track.
You can also change the layout so you can use more screen for the Library. (The Library in LumaFusion doesn't require import from the Photos app - those clips are always there).
LumaFX could benefit from a larger import window though, so I will write that as well as the undo/redo wish into our feature wish list.