You don't have to take the intake off to clean it with the seafoam. With the truck running, pull the brake booster line, or the PCV line off of the driver's side valve cover, and slowly pour the seafoam into the line. It gets sucked into the intake manifold and cylinders this way. It will make the truck cough and sputter a little, this is normal. After you've run about 2/3 of the seafoam into the intake, turn the truck off and let it sit for 30 minutes. After that, start it up and go drive the piss out of it - you'll be billowing white smoke out for a few minutes though so it's best to do this at night or in a rural area. Try to take it on the interstate if you can. The white smoke is all of the carbon desposits burning off, so higher speeds/RPMs help drive the particulates out. Drive it around for 10 minutes or so and you're done. You can put the other 1/3 of the seafoam in the oil, run it a few days, and then change the oil.
As for the TB bypass - the throttle body has two lines running into it that circulate engine coolant through it. This warms the intake charge and helps the engine get up to operating temp a little faster in the winter. Those lines also make it damn near impossible to clean the throttle body because you have to disconnect them to take it off...and they're nearly impossible to disconnect. I cut them off, capped the tubes going into the throttle body, and used a barbed fitting and small worm clamps to connect the two pieces of hose together so they bypass the TB. This makes the truck take a little longer to warm up during the winter, but also keeps it cooler during the summer and keeps your IATs down. Makes it a HELL of alot easier to pull the TB off and clean it, too. Some people tout it as a "performance" modification because it keeps your IATs a little cooler, but if there are any gains to be had I sure can't tell. I did it soley to make it easier to clean the TB.
There are better write ups with pics on here somewhere, just gotta seach for em. Thats it in a nutshell though.