Probably just a terminology misunderstanding, but the ports collection is not necessarily part of the Freebsd userland. It can be, but doesn't have to be. There's a complete functional userland in base.
Please remove that again. It's a very recent change, so portlint wasn't updated yet. But there were already a few "hunts" for these lines re-appearing – with the change to GIT, they are pointless and shouldn't be there any more.
Yep, kind of bad timing, cause normally,
portlint is a valuable tool when learning. Over time, you will know when it is fine to ignore a warning from portlint (I have that situation with one of my ports, which is pretty complicated and "non-standard"). And normally, a "fatal" can never be ignored, except for right now 
But looking at the commit quoted by diizzy, this is already addressed.
Yep. It warns me I should add an NLS option to my port. But the whole thing fails to build if you try to build it without NLS enabled. So it's not optional. Still portlint keeps warning me about it.