You have it right. The two links will snap together with two pins. A rear sight, some lube and a loaded magazine and you ready to shoot.
No, the one in the OP is a mid Length gas system which IMO is the best gas system. But yes you would have a complete rifle very similar to the one you linked.
I'd googled it to learn about it, but thanks I appreciate it! I meant more that I'm lost with rifles in general.cfr, if you are saying you are lost concerning mid lenght gas system, the simple explanation is as follows. The 16" barrel can basically have a mid length or carbine lenght gas system. The difference is in the placement of the gas block (which in your case would be the front sight post) where the midlenght gas block is closer to the muzzle than with the carbine lenght gas system. The mid lenght system is said to result in less recoil, less wear (mainly as to the bolt) and a longer sight radius.