Rig: 2001, Ford F250 Crew Cab, 7.3 PSD, Auto, 4x4, 3.73, 125K.
Mods: Stock + Stage II CAI, 4” MBRP Turbo Back.
Use: Daily Driver, Work, Tow and Play
So usage is "everything" 
.
Looking at the following tunes, but open to suggestions:
Stock
High Idle - 1,100rpm
40hp Heavy Tow
65hp Daily Driver
80hp Performance
120hp Race
Questions:
What tune offers the best average daily in-town & highway full economy when running empty? When towing <10k?
Depends on your right foot. Optimizing operating characteristics by way of aftermarket tuning always helps a little as long as you can control your right foot. The 65 and 80 HP tunes will probably be your best bet for steady-state driving (like interstate or highway cruising).
Can Lope Idle be combined with say 120 Race?
In this way, when running 120 Race setting at the light idling, it would be Loping until I nailed the fuel.
Any negative impact to doing this?
I would assume so....however I think the transition between the lope idle and regular operation may be a little hard on the engine. That's a question for Bill. I wouldn't do it in my tuning.
When in High Idle, does it remain drivable? (I understand that the Auto Tranny will pull if in gear, but in my case, this is desirable)
It should be...just that you'll be awful hard on the brakes.
Can High Idle be combined with say 40hp Heavy Tow?
Like DJ said, high idle can be implemented in any tune. It's a simple procedure. However, it's up to Bill whether or not he'll do it.
Do you offer a High Idle that also closes the EBPV, for faster cold warm-ups?
If yes, does it follow the factory time delay before closing the EBPV and idling up to protect the cold engine?
The EBPV should already close by itself once the idle increases automatically. I suppose it is reliant on the base PCM program, but you're probably dealing with a VRAA6 or VRAA7 hex code anyway and it SHOULD do that by itself. Otherwise, yes, it is very possible for Bill to program the chip for your desired operation. The time delay can also be changed very easily if you want it to idle up earlier in the warm-up cycle instead of waiting 2 minutes.
At what HP tune level should I become concerned with shortened longevity of the engine and tranny under continued use?
It all depends on how you drive it. You could run a 120 HP program all of your truck's life and never have a problem. On the other hand, a 40 HP tow program could kill everything in short order if you drive your truck like a rental car.
Are the factory TC Lock/Unlock routines maintained?
They can be but there are changes available for the better.
At what HP tune level do I become concerned about additional modifications, say head studs, HP Oil, Fuel Filters, Rods, etc.?
Anything above stock.......if you are looking for more than a "do everything well" kind of truck. For what can be had with stock AD injectors like your truck has, you really don't need any of that. A higher-capacity HPOP is always a welcome addition to any truck.
Less directly related:
Looking to future, for highway economy, and street level performance, which is a better upgrade, Propane or Water/Meth? I tend to think Propane is the best overall solution, base on its history being used on Semi-Trucks. I am really looking at these two options as a way to increase fuel economy through better fuel usage.
If you're looking at propane for a power-booster, then forget about it now. Any amount of propane that increases power much (if any) in the Powerstrokes (especially with powdered metal rods) is going to kill it quickly. Water/methanol is your best bet.
Looking to future, may also start running a B20 blend. Any changes or consequences to doing this without additional rig mods? Different tunes required?
Commercial B20 shouldn't need any changes.
I read though forum, but could not find answers that seemed to fit my questions.
I originally e-mailed these questions some time ago, but having not heard back, thought I would give the forum a try.
Thanks for your time to respond, I’m sure it is in short supply.