This has been my experience as well. Actually, it's worse. I actually managed to earn a bunch of points on SO by finding some questions that needed better questions...but it took a long time to get there for all the usual reasons of not wanting to jump through those hoops or spend lots of time trolling the site. Then I did something really stupid: I had an outstanding unanswered question about a really obscure subject, and I thought well, is someone answers this they deserve a bounty, so I added one. I didn't really care about rep, and my question was hard, so I put most of my points into it. It didn't occur to me that spending most of my rep would cause my account to degrade back into noob mode; I was thinking I had earned the privelegs of a normal user and they were mine to keep.

Worst of all, my question went unanswered, and the bounty was just claimed by the system.

I haven't earned back enough reputation to be a normal user again, although I have stumbled across many SO questions/answers that could use my insight. Since I can't use the site correctly, I just leave.

You do realize that they can't just grant anyone the right to edit questions or answers and that they don't have magical insight into your abilities? I don't know how you propose to solve the problem of automatically allowing those that have ability to bear responsibility, but I don't think there is any site that does it better than SO.

  It sucks for the casual user.

I'm a casual user (I have 1.5K rep and subscribed reasonably early, so we're talking about 10 decent answers per year) and I don't think so.

  Which I already wasted trying to help someone in the 
  first place.

Then SO is not for you, because SO only makes sense if its users want to help others, for whatever reason. I personally like trying to explain something clearly and concisely and I like solving the problems that are sometimes posed. I answer questions for my own good, but it is gratifying that someone else also profits.

A casual user should at the very least be able to flag an answer for review by a more senior user (and earn rep). For example, fixing broken links, or Facebook API changes that make old answers invalid.

I see your point, but I really don't think that 1.5k rep qualifies as casual in the context of the discussion.

I have answered 76 in two years and 4 months (and posed 5). Let's be generous and say that's 1 answer every week. Is that not 'casual use'?

Over a sustained 2.5 year period, not really. I mean what percentile of activity/reputation do you think you'd be in for all members in that period? I'd guess well over 50... perhaps 75 or 80?

Programming is my full time job and I ask questions on SO somewhat regularly when I get stumped, and occasionally peruse for questions I can answer, but I don't make any efforts in particular to raise my rep for its own sake, and I just reached 100 rep after being a member for a year. I feel like I fit into the 'casual user' camp that he's referring to in the OP since I'm still pretty limited in my participation even though I FEEL like a somewhat invested member of the community. But I don't think these issues would really apply to you at your level of activity (and kudos to you for that, btw :) ).

The problem is that I want to help, but I can't. If they've added what other users have suggested, that anons or newbs can provide answers/edits that have to be approved by a more senior user that probably covers about 99% of the situations that I'm concerned with.

You're right that the system can't know my insight. But the community can. It is a community right?

I'm cool with going through some sort of approval process. If it means that it takes a few extra minutes for my changes to get in then so be it.

I think this is key. I answer questions to help other people. I also answer them to help improve my own ability to explain solutions to programming problems. Usually the problems are ones that I myself have dealt with before. I tend to answer questions pretty late, in a few relatively low-view tags, and I can tell from the view counts that maybe 10-50 people at most ever read any of my answers. But usually the asker of the question sees it and finds it useful enough to accept it.

This week, the ability for anonymous, 0 rep users to edit questions was added. They go into a queue where other users must approve or reject the proposed edit, but you can drive-by suggest those improvements now.