Sounds good!

One hide is actually fine for a tub, as the area is more enclosed. Perhaps a branch or a little fake plant would be good for extra security.
Aspen is good.
Not at all necessary to feed in a separate place, most people feed in the enclosure with no problems with aggression etc.
Do you have a thermostat for the UTH? The exoterra kind that's cheaper should be fine. Even a light dimmer could be okay, but it's not reccomended.
The half UTH over the tub sounds fine, they just need a cool area incase they get too warm.