Taper pins on FSB - It's a trick to knock these out...Beat the crap out of it...Not your FSB or gun. Putting them back is a process to. Align one side with the appropiate sized punch and tap the other side in to 90%. Remove the punch and then tap the other side in to 90%. Then beat the things back in like they owe you money - OK, that might be too hard. If you don't do this, you will have the FSB cant and you'll post some sobbing story about how the MFG of the barrel didn't do something correct. Nope, it was YOU.
The roll pin on the gas tube is easy to remove with a roll pin punch. Use something like the Brownells Pin in/pin out block and you will have no issue resusing or losing this. I recommend the roll pin holder set. I have never dropped or lost one with this punch set. Try is without, and you will probably tap and head a ping...Good luck finding the roll pin. $40 is cheap compared to waiting 5-7 days for a new roll pin and paying sometimes expensive shipping if you are cunning.
I would not remove the snap ring or the delta ring off the barrel nut. I would remove the entire thing as is and store is in a tupperware container with all the other pieces like the handguard cap.
I would NEVER reuse a crush washer...They are stated to be a one shot deal. Have people reused - Yep. Issues - not many, but a few. The idea is this thing crushes as you torque it down. There is no torque requirement, and people will post something like 30-35 ft pounds - that is for the peel washer. The crush is minumum of 90 degress and 460 degrees, so you have a WIDE range to time the stinking thing.
I recommend you buy a FF tube that doesn't use the stock nut. The quality of these aftermarket nuts is amazing, and the standard armorers wrench should work on the FF tube nuts. I have used the Troy TRX and the YHM diamond plate FF tubes, and each has likes and dislikes. You will hear about the Troy quality, and I don't disagree. However, I really don't like the two screws that clamp the FF to the rifle - Sort of a wierd arrangement since the rest of the rail oozes quality. I LOVE the YHM swedge locking ring. It requires a tool, but there has been no issues. Alignment of the Troy is a no brainer - Probably why so many people rave about the Troy. However, the YHM can get the same great results with a little time and patients.
If you have any issues or questions, PM me directly. I bet about 20 post will follow this bashing me with opinion...I got it boys, I got it!
Almost forgot...
Link (Section 5)