1) Your first complaint is a nonstarter. The only difficult open-world spawns are World Bosses (very obvious to spot - usually ginormous) and the occasional "elite" area (maybe one small part of a zone, some zones don't even have one), which is very obviously NOT a normal place (you're only taken to "elite" spots by "elite" quests that are very obviously labeled "elite") and they do NOT look the same as non-"elites".
Having not played this game, I wasn't aware of that. I was referring to other games I have played, most notably WoW, in which elite enemies almost never look any different from the non-elite enemies nearby, and have no determinable reason for being ten times as strong.
And there is always a good reason to have pockets of harder enemies - MMOs are supposed to be team centric (with the allowance and occasionally the encouragement of soloing - and I say this as a die-hard soloist) - having pockets of difficult enemies encourages team play, and it also gives those minmax crazies a place to test their ridonkulous builds against enemies that are supposed to be taken down by multiple players.
At the same time having the difficult enemies confined to these little pockets, which are never anywhere near as numerous as the entire rest of the game with easily soloable enemies, encourages people to never team up unless they have to. Compare to CoH where outside of a few rare exceptions there was never a penalty for teaming up. While in most MMOs, and apparently this one as well, if you team up when you're not supposed to everything suddenly becomes trivial, usually to the point that they may as well not bother spawning the mobs at all for how much challenge they present. Because, you know, why would I ever want to keep doing what I was doing rather than stop and do something else just because a friend wanted to join me?
Dungeons are where you find most of the difficult enemies. I solo'd almost entirely and never had trouble with surprise "elites". Of course, I think maybe I am more observant than the average MMO player, so maybe YOU might have trouble with surprise "elites".
I don't, usually. I just disagree with elite mobs as a concept. CoH's method of throwing larger groups of the same guys at you was infinitely superior, in my opinion.
2) I never once had any trouble with the ramping-up respawn rate in high-traffic areas. After all, like most MMOs out there that do it, the ramp-up mechanic only activates when people are killing them faster, so to keep up with the people in the area. So more critters in the area is balanced by more people killing them.
That's just me taking the worst possible outcome. Again, I haven't played this so can't directly comment on it, but I've played games with stupidly fast respawn rates and it's just as infuriating as I said. As an example, in some places in Guild Wars 2 it's possible to stand in one place and fight the same three enemies literally forever, because they respawn almost instantly after you kill them. I doubt this game is that bad, but still.