The X-valve parts kit does not come with carriers. They only come with the Level 10 bolt kit, or you can order them individually. If you don't have any, you should get a few from size 0 to 2.5. You won't need to buy the one(s) you already have.
You shouldn't ever get bolt stick when you aren't using a bolt spring. There will always be enough force on the bolt stem because there is nothing pushing back. The fact that it worked without the bolt spring using low pressure air is a positive sign. Make sure the bolt is fully in the reset position, or the sear won't rotate forward to open the on-off pin. This holds true, even if there is no bolt spring. When you are testing, make sure you push the bolt back when it is aired up. You can push the bolt back with a squeegie or dowl through the front.
Often when you install a new carrier and oring that is too tight, the bolt doesn't sit in the reset position due to the spring not having enough force to reset it. This is bolt stick. The same bolt stick will prevent the gun from firing even if it is in the reset position, because the air in the chamber does not have enough force to overcome both the spring force and the friction force of the oring on the bolt stem.
Except for the Automag in front, its usually the man behind the equipment that counts.