well you have quite a few ideas, but I see some of these problems differently.
1) I don't see a problem with Legolas and his armor. Sure maybe there could be something done to give Lolo Legolas and Hunter Legolas a different look, but it's nothing really important. He might be recruitable with Lorien but it's still the lotr Legolas, so it makes sense that he looks the part. A possibilitie would be that like Haldir, he would start with his elven clothes and with a level up get his leatherarmor. If this is possible without a passiv ability, I don't know and it also might be strange since he doesn't get better armor. So i would simply keep his look.
2) Tauriel being recruitable on Mirkwood is a map easteregg/feature, so I don't know if the ET wants to do the same on a other map, but it would somehow make sense.
3) I can't say anything about that, maybe thats just a bug in the english version.