Pleeson you're fine, that light comes on for me too anytime I boot the engine, (if it's the same one, lower left corner, looks like the outline of an engine) my mechanic tells me it's just the pollution sensors not liking the extra fueling, once you pull throttle they settle down and like you say it shuts off. They won't put you into limp mode or anything like that and any chip is going to cause them to fault, they are a bit too sensitive, somewhat like residential smoke detectors!
For engine advice, this is the third 7.3 I've set up, one non turbo and two turbo. I've always changed the intake first, followed by the exhaust and while these two modifications don't' seem to make that much difference the chipping is where the diesel really opens up!
As, far as I know, there's currently two types of chips, both of which I've used; the inline type you plug in that interrupts the signal and newer type that actually reprogram the ECM, Engine Control Module. The caution I hear on the newer reprogramming ones is that some Ford stealerships (get it?) are dedicated to finding these types of chips in order to block warranty claims and generally blame any problems on that they can't fix.
My current chip is the Bully Dog, a five step instrument that reprograms the ECM and can also read and erase codes. I'm on the second step, light tow, (8,000 lbs. which doesn't seem all that light to me!) I have in the past set it to heavy tow but took a miles per gallon hit and the EGT, exhaust gas temperature got higher than I'm comfortable with. I've also set it to performance just for fun while not towing and laid rubber all around town but had to dial it back down because tires are about $300 each!
Anyways, EGT and RPM is how I operate my 7.3s, if either get too high I just pick another gear and go a bit slower.
Here's to safe towing and safe boating!