No, no and probably not.
FAs have broken and jammed more guns that problems solved. Chamber checking? Really. Check position of top round in mag, insert mag, drop bolt, check that round stripped off mag, reinsert. Even the tactical crowd does it this way. I've done thousands of reloads on the AR platform, never did a chamber check and in the vast majority of cases, there was no time to check. Load and go. Most of my ARs have plugged FA ports anyway.
Chrome lined barrels are less accurate, but last about twice as long as an unlined barrel. Unless you get a match barrel with a tight chamber, the reliability won't be any different. 3Gun match barrels typically have a littel looser chamber and the .223 Wylde so they can run everything with accuracy and reliabilty.
Dust covers are not needed, but they are nice if you are hunting, in dust or rain. I have them on all of my ARs except my heavy varmint rig which I would not be shooting unless the conditions were nice anyway.