QEVs don't need it usually. Unless you cheaped out and got so no name brand, QEVs come with a black rubber gasket.
I think the barbs may also, if not, I doubt they'd need it, maybe just a little dab, then dry is off on a rag.
And for your last one, It's fine, just don't use too much or anything over blue, no point unless you want it not to wiggle. I like my ram with a little freedom.
If you don't have anything nice to say, say it on the internet.