I think that is overkill.
A UV while you say there is no reason not to the reverse could also be said, there is no reason to. I have a UV over my Ball tank but that is because it has plants inside....not for the snake. She is hardly ever out when that light is on.
As to the RHP and a heat bulb. I think you may be underestimating how well a AP cage will hold the heat. One or the other is all you should need. Unless you are dealing with some really cold temps.
Should the lights be on the same end as the RHP?
I wouldn't think so. Like I said you should only need one or the other. I would stick with the RHP as you don't have to worry about a bulb going out.
How much of the enclosure should the UVB fixture cover?
No clue and I wouldn't add it unless you have an actual need.
What kind of basking bulb should I use (was thinking halogen)? And how many watts?
I would get a 60w and a dimmer. If you use both this bulb and the RHP neither will need much power so a tstat for both would be best but at a minimmum a tstat for the RHP and a dimmer for the bulb will be needed, IMO.
How many hours per day should they be left on?
I have lights in most of my cages as well as day light in the room. At night I have a floor lamp with two bulbs for viewing at night. I just run them on a standard light cycle. When it is light out the lights are on and when it's dark the room is dark.