And in which other MMO is it necessary to go to another race's starting area to get high enough to go to the next quest hub? In my opinion, it's bad design. If an area says level 1-15, it should at the very least contain enough content to bring you up to level 15. So not only is the content in the areas lacking, but now you have to go to another area to bring up your level. So if I start a human and plan to have one alt of each of the remaining races, chances are I'm going to play through the starting areas multiple times. I can't experience the majesty of the Caledon forest with my Sylvari character, because I've already experienced it with my Human when I needed to get 3 extra levels because the human starter area didn't contain enough content to get me to the human starter area's level cap.
But it does. The problem remains that people want to rush through the game to get to the end-game (for whatever reason I'm not aware), and in every likelihood, they get to a point where they've "completed" the map and find they're not high enough level to go to the next one up. But in reality they've probably also missed about half the dynamic events on the map. I had this problem in the beta, when I was rushing as well, but with the eventual release, I completely slowed my pace and wandered around a lot, and I have not once, with any of my 7 chars, run into this issue.
The entire game is engineered around the concept of encouraging you to explore, and it rewards you for it.
You say it's bad design, but I think it's an awesome concept. This of course, is a matter of opinion, and different styles of play, but you hate going back to low level content. I love it. I love the fact that I can go back to a low level area and still be faced with the reality that I can get killed if I don't pay attention to my combat; added to that, name one other MMO that still gives you drops and xp in a low level area. And of course, it means that these areas are always populated, and you'll always find people to play with. As opposed to any other MMO where the starter levels are generally deserted.
As for DR, it's not really something you hit, it's something that's always there. According to your activities, you get assigned points to DR. For each point you have, your item drop is halved. Getting points is so ridiculously easy that anyone who spends more than half an hour in an area ends up hitting the DR multiple times. This is especially ludicrous in Orr, where the entire map's 'quests' consists of a bunch of dynamic events. Hitting the Karma DR there happens ridiculously fast, meaning that while leveling in the map you're likely to, at one point or another, experience your karma income trickling to a standstill.
The whole thing about the DR is that it's supposedly there to prevent bots, but in actuality it's just there to prevent people getting rich fast. ANet tied their micro-transaction currency directly into the game by making it tradable for gold, so this means they have to tightly regulate the economy to prevent the crystal cost from falling too low. Making gold income slow also helps in that it might coerce some people into buying Crystals with real-life money so they can trade it for gold. The whole thing is actually pretty genius. That's why something that is pretty much a core of MMO gameplay (grinding) is punished by the game system in GW2.
I'm aware of karma dropping the longer you spend in a zone - especially if you repeat the same events. Again though, I've never once experienced my karma income dropping to a standstill. But I don't spend hours in the same zone doing the same thing over and over. Even in Orr the decrease, after being in the zone for an hour, is laughably negligible. And if you switch zones, you can pull in ridiculous amounts of karma. Especially as a level 80. But then again you don't seem to like doing that.
The same thing applies to making gold. Really, I don't push much, but if I really wanted to I could pull in a couple of gold in a session. If I used crafting I could pull in even more. Onslaught apparently pulls in between 10 - 15 gold on a daily basis, but he has more patience than I do - which includes several dungeon runs in a row. I can handle one or two at most, but I've never been a huge fan of dungeon instances, much to the amusement of my fellow guildies, but this is arguably one of the best ways to earn money.
Chasing the regional bosses is another way, since you're guaranteed a rare drop once a day.
On top of that there are your daily achievements, which will likely be another point of contention, but guarantee you a minimum of 6.5k of Karma - but in all honestly you can get them done in about 30 minutes while just randomly running around and killing things. Monthlies give you 60k, and are easy enough that you can complete them in the first week of the month already.
Don't get me wrong, GW2 does a lot of things right, like the combat and the way it handles PvP. However, after a month or so of playing the cracks start showing and this game really starts to feel like a F2P game that you had to buy to play.
All this, plus the fact that they still haven't sorted out the horrendous performance issues that plague the game, as well as the numerous serious bugs in quests that still have not been fixed, months after reporting them, means I'll likely never touch this game again.
It's a pity, but I do think your approach to the game, as well as your playstyle probably means that GW2 isn't best suited to you. I've been playing it pretty much non-stop for the past 7 months, and what you see as cracks I see as minor inconveniences, which for the most part get fixed pretty soon. As for bugs, the only ones I still encounter lately are the odd dynamic event chain that gets stalled.
New content gets added on a monthly basis, so there's pretty much something new every month, and even when I've played through that, I find there's always something to do - which right now includes exploring the different race-storylines, and messing with the different professions. I can see myself still playing GW2 for a long time to come - by the time I eventually finish my legendary I'm sure there will be something else for me to aim at.
I mean then I can mull over my built 
