Looking for chip, so some questions...

[MtPaul401]

I've been reading great things about PHP chips on the Powerstroke forums and have been thinking seriously about the phoenix 6 position chip. I need some info, since the chip thing is greek to me.
I have a late 99 F350 powerstroke with an automatic. Mods that came with the truck are:
Banks big head turbo
Banks stinger plus chip
Banks transcommand
4" exhaust
I added:
diy Napa 6637 intake
HPX crossover line

This is my daily driver for work and I somtimes haul some heavy loads, up to 1800 lbs or so. I tow rarely, maybe 6 or 7 times a year just a camper, probably weighs under 5000 lbs.

My questions are (possibly dumb but...):
any problems from having the Banks chip in?
can I just put the by pass plug in the trans command and call it good?
I'm currently getting around 16 mpg around town, about 17 on the hwy, will I see gains with this chip? I'd like to get better, of course, if possible which is one reason I'm looking.

I was looking at the available tunes and thinking about this setup with probably 4 settings for my budget:
Stock or modified stock
80 hp light tow - I'm assuming that would work for hauling..
65 or 80 daily driver
maybe 80 or 100 hp performance
which one of the last two work best on the highway?

If it makes a difference, I live in Montana so have some mountain driving.

Thanks for your help.