Changes have been made to the article to answer your questions, and I will also answer them here.
1. I have widened, heightened, and lengthened the APC to make it a little more believable, and added a blurb that acknowledges that while carrying PA infantry, that the interior is cramped and uncomfortable. This was originally a Sigma article that we updated, and Sigma was always a little screwy with vehicle proportions and equipment. This must have slipped right by us.
2. It does. It's a simple armored box powered by a hyperefficient fusion generator - when unloaded. However, the caveat is when laden with ten power armored soldiers (assuming they're all in Hostiles that's twenty tons, just the suits) I have debuffed the speed, so to speak, to make it only about as fast as the Maximus tanks it will inevitably accompany (85 km/h at its absolute most, that is on completely clear roads; combat conditions will inevitably make it slower).
If it were carrying 'light' infantry then their speed would still be attainable, since such a load is negligible for the UCF-04a, but the drawback here is that it's not carrying power armor - just goobers.
3. Added a blurb about the commander's and driver's positions, but truth is, there's not much to tell. The Commander's seat is a simple set of joysticks for the Remote Weapon System - almost everything else is handled by the Armored Vehicle Crewman uniform. The driver's is even more bare bones, and is merely a steering wheel.