I'm just listing out the most urgent problems with existing features. Well, they might be the ones most plausible for me to do with nothing than a Final BIG, too:
1 - The basic factions are not selectable even as the new factions use Juhziz, USA Boss and GLA Boss.
2 - The colony drop belongs to Zeon.
3 - Beams hitting objects that are perpendicular to, or even behind, the firing position.
4 - The VA-3s have no attack (need to double check)