Not gonna quote, but heres my 2 cents... You made the right choice. Thats all there is to it. People would have been upset no matter how you left. They WILL get over it. A few wont, but they would have been pissed no matter what. THEY need to respect your feelings and desicions... and also try and figure out the problem that brought you to that point.
As for the other guild leader responding the way he did... how could he NOT have time? He had time to sit on his ass and not push the invite through for a few days? Whats this say for his execution on pretty crusial matters. He seemed kinda pissed. But he can only be pissed at himself for not having better execution on matters at hand.
Drama was the way to go. THEIR GL's response seemed more than resonable... it was very understanding.
Heres my point... through the whole ordeal... who seemed to care about what you did the most (in a positive way)? The guild of strangers. I think it will all be okay for you. Dont worry.
And... it IS a game. You pay your money and deserve to have fun too. When it feels like a job, ya gotta change something!