Browning, your Factory Crimp die is the one in the bottom right (but you already know that). In your bottom left is your bullet seater, and the top right is your full-length sizing die. To the right of your full-length sizer are some ear buds and to the left, a pair of Optimus shades.
The answer to your first question is no, the FC die doesn't have an adjuster knob - it adjusts by screwing the die in or out.
Your second question: Yes, the Collet neck-sizing die will have a decapping pin, but the top won;t look like the top of your full-length sizer. Instead, the decapper floats inside the die body, as does the collet, and is stopped by a flat-topped aluminum cap screw. Again, the Collet neck-sizer will take the place of your full-length sizer when you want to neck size. When you want to full-length size, remove the collet die and replace with the full-length sizer. You can't use them both at the same time, or one after the other, at least I can;t think of any reason why someone would.
Third question: You might think about getting a dedicated Lee Universal decapping die. It's sole function is to deprime the cases. The body of the die (inside) never touches the case. The reason you might do that is: when you come back from the range with empty cases, you can decap them in that die without spreading any dirt or carbon in your other sizing dies. Once decapped, you can clean the primer pocket, brush the inside of the neck, and tumble or whatever. Then your cases are clean and ready to be either full or neck sized. Even if you use a dedicated decapping die, don;t be tempted then to remove the decapping pins from your sizing dies. Both the full-length sizer and collet neck sizer depend on the mandrel being in place during use, whether you actually use it to deprime or not.
What I recommend you do, if you haven't already is to take all the dies apart. Clean them in mineral spirits or acetone, inside and out (external threads too with the spirits and a toothbrush). I use acetone, q-tips, blue paper shop towels to twist around inside the die bodies, and a toothbrush. The entire die gets cleaned, including every plug, collet, outside threads, lock knuts (inside threads), and even the inside threads of the press where the dies screw in.
Full-length die: use two appropriately sized wrenches to loosen the collet at the top of the sizing mandrel. I leave mine in the press to do this, unscrewing the die just enough so that if the die turns a tad it won;t over-tighten the lock nut. Once the collet and mandrel (decapping pin) are out, clean everything inside and out. Tighten that baby up
tight when you put it back, making sure the end of the decapping pin is about flush with the top of the collet nut. When reassembling, I always lay the die on the bench. That way the mandrel can be positioned where I want it and I can tighten the nuts without have the mandrel sliding in and out and having to fuss with it.
Collet neck-sizer: unscrew the aluminum cap screw and remove the sizing mandrel (decapping pin), the plug, and the collet. You may have to tap the collet out (from the bottom out through the top) with a dowel and a mallet. Some guys put a little lithium grease on the outside top of the collet when reassembling. I don;t, I keep it clean, dry, and shiny. IF you use a little grease, use it sparingly becasue, sooner or later, the grease will work its way between the collet fingers to the inside of the collet, and will then get on your case neck. Who wants that?
Bullet Seater: Unscrew the seater plug adjusting knob and remove the seater plug.
Factory Crimp Die: With die in the press, take a mallet and large dowel and tap the crimp collet
down out through the bottom of the die.