I think I can already answer some of Plejaren's problems. I've also had that white sphere problem. What I did is that I went to the unit's Actor, then I changed the first 5 Art - Model to the corresponding base unit (in my own case, Baneling). As for getting a unit from one map to another, I'd guess you can just Copy every related object and Paste them into your map.
However, I'm also having the problem of Tentacles. They're attached correctly, they deal damage correctly, but they don't stretch and I don't know why. My Baneling also doesn't produce any sound, from both the tentacles' attacks and from death.