I understand your concerns, and feel that, to an extent, they are well founded. However, regardless of whether Seattle allows pay-no-play for their games or not, other chapters do, which means that characters based in Seattle will have the ability to pay-no-play in other chapters and still gain build. This decision isn't new, Seattle has allowed pay-no-play for some time. There are a number of players in Seattle that do pay-no-play in other chapters, and even if Seattle didn't allow it in their chapter, those people could still gain that build.
It is my hope that allowing people to pay-no-play will similarly encourage people from other chapters to send us money to increase a number on a character sheet across the country. For Seattle, there is no new downside. Eliminating the pay-no-play policy across the entire alliance would be the only way to remove the ability from someone here to suddenly 'buy' levels.
The only way I foresee someone trying to 'abuse' the pay-no-play system in Seattle would be to not attend events and then purchase them with money. This brings up two points. The first is that, since Seattle gives gobbies for cash donations (and even if they didn't, it's not that much more difficult to turn that cash into makeup, paper, printer ink, etc), someone could get the gobbies and backblanket the event anyways. The second point is that if someone wants to build up a character that they don't show up and play, who cares? There could be an 83rd level PC on the books somewhere, but if they never play, it doesn't affect the game. (Heck, according to the treasure policy, if they pay-no-play, their loot gets added in for the weekend.)
Finally, this: "Pay and get gobbies that we'll use for your event fee, and if you don't show up we'll put the money towards someone else who can't afford it being able to play too" used to be pretty much how NPCs got to play cheaper, except it did't come from just one person pay-no-playing, it came from PC fees. Anymore, there are slightly higher NPC fees to ensure site cost is being covered, since we seriously need more players. (Seriously.)
~Matt