As for the TB, disconnect the battery prior ever starting. Clean the TB, and reconnect. But, no the truck shouldn't have any trouble starting.
For seafoam, Put 1/2 can in the PCV valve (Located on Drivers side valve cover, under metal air intake support bracket) and 1/2 can in the brake booster (Drivers side firewall, look for a little green nozzle, the hose under that is the line you want)

The PCV line runs to the Drivers side of the intake, the Brake booster runs to the passenger's side. They meet in the same location, but i do both just for kicks.

Seafoam in the oil: it's 1 1/2 oz per quart of oil. So, the 5.4 uses 7qts with filter, put in 10oz of seafoam, run it for 300-500 miles then change oil.

For the gas, it wont help a whole lot but it never hurts. Only MAJOR improvement you can do is buy higher grade fuel (not higher octane, just better fuel in general) Personally, I don't. I but it wherever is cheapest at the time. I wont preach the importance of good fuel, frankly, because I dont think it makes a whole hell of a lot of difference.

 

Awesome, thanks for the help!

 

I have an '04 4.6L. The PCV is on the valve cover. My question is, is it the one on the left (driver side) valve cover? The hose on it runs to the intake tube just behind the MAF sensor. There is a similar valve on the right side valve cover and the hose from it runs to the rear side of the intake manifold I think.

 

just to add, if possible; distilled water in the antifreeze mix . and washer fluid not tap water.
in the washer reservoir.

 

I don't know about the 4.6L I would take the side of caution and go with whichever has vacuum and causes the truck to run strange when you remove it.