This is a good list of options you mentioned there. But to be honest: I would not use them all. This would create a lot of confusions. It is much better to master one of them perfectly. Since I have bad experiences with Truespace I would rather learn Blender. This alone can take a few years but will be worth it. Another unwrapping and animation tool is not needed. But maybe Milkshape and Fragmotion can be used for export.

Regarding the UI: I worked with MED, Gamespace, Lightwave, ZBrush, Blender, Modo, an older Max version, Cinema4D, Reflection, Monzoom, Milkshape and UU3D. It always takes time to learn the UI. Truespace has a very unique UI and takes some learning. Lightwave took me some time but was absolutely worth it. Blender and ZBrush takes time. The most different UI is the one from ZBrush but still it is the most used sculpting tool among artists. So this was not a big barrier for the ambitious people out there.