Just a few I thought of, but I don't play ranged.
Terror From Beyond
Kel'sara: targets ranged in P3
Kephess: lots of movement
TFB: Dodging spit in P1; movement and mele range in P2
Scum and Villany
Dash'roode: ranged stuck on adds; frequent movement between generators
Titan 6: Dodge air strike; pull in during soft enrage
Thrasher: Dodge merc missles; boss kiting and cleave avoidance
Nefra: ranged usually stuck pulling droid from group
Draxus: Bulwarks require mele range
Brontes: Fingers require mele range
Council: Ranged stuck kiting Raptus?
Maybe others, but I have to run.
While many of the bosses and mechanics you mentioned are very valid arguments there's a couple things I noticed.
For Nefra you're wasting your Rdps's time+dps by having them attempt to pull the droid, its on a random table and tbh if people can't pay attention and move out of red they probably should go back to EV/KP.
For Kel'sara it can go either way, if dps are killing adds then they can be targeted as well, while not as likely, still has happened to me a couple times. (NiM only, as hm adds are a joke.)
Kephess isn't too bad for ranged, they can pretty much hang out in the middle until just before he targets someone, however for nanites it can be a PIA.
I was planning on listing more but then realized that the only class that can truly make 90% of those arguments obsolete are snipers/slingers. Their roll + hunker down(SS) make the fights trivial.
More or less both classes have their ups and downs, I do agree that bosses should pull those in cover to make fights at least a little challenging for snipers and slingers. They can already ignore doom and other mechanics that hurt the rest of the classes, they should have something that hinders them, or make mechanics in future fights kill them through the roll. I'd also like to say that I play a slinger, sniper, and a sentinel, so this isn't some melee whining about op ranged.