I think you're overexagurating the problems of the patch quite a bit.
Undyed quivers was a bug... is it really that serious of a bug? I mean seriously. Is the color of your quiver THAT important?
The report of an unbonded pet was most likely the result of someone failing too many commands. A lot of people have been cutting corners by not having 120/120 taming/lore and still trying to control high end pets. Naturally, these pets go wild sometimes.
The removal of guard zones happened because it was overlooked when the devs pulled the event content out of pub 55. You should be happy they did that... It shows that they would rather bump the release of content back than release the content before it's ready. Since the event content was at one time part of the publish and the decision to pull the event stuff out of the publish was made kinda late, it's not that surprising that something accidentally got published.
The house placement issue only happened becuase the house placement blocking code (part of the event stuff) was pulled out of the publish and the gaurd zone disabling flag was missed. This was a small mistake that was fixed very quickly.
The devs will probably talk about the shield disarm in the FoF. I think it's highly likely that shield disarm was not possible because of a bug. I know there was a time when you could disarm shields. I suspect that the devs discovered a bug that was preventing shields from being disarmed while they were making it so spellbooks could be disarmed.
I think the fact that the devs bumped the SA release back by a year and completely retooled it says a lot about how serious they are about releasing working content. Sure, bugs get through every now and then, but the devs have generally been fixing more than they've been breaking. In some cases they fix something and people complain that they broke something. Players get used to abusing broken things in the game to the point where fixing the broken thing makes the players think a bug got through.
I certainly think that the last 3 years of UO have made UO a better game. UO is like an ocean liner. It takes a really long time to turn it around, but once it's moving in the right direction, it can really move. I think the devs have effectively turned the ocean liner around by fixing bugs rather than pushing out tons of new, buggy content (for the most part). The critical element will be for them to release relatively bug-free content when they add content.