Darn, Alan, sorry to hear that! It does seem real strange that oldscribe and myself are not having any issues at all, after applying the patch. Also, at least on applicable sites I visit, I am not seeing any reports of problems with the patch.
When you started in safe mode and ran Disk Utility, what Disk Utility processes did you run? From what I see about Disk Utility, you can Verify the Disk, Repair the Disk, Verify Disk Permissions, and Repair Disk Permissions. Unfortunately, that might not be enough, and thus possibly a more robust Disk repair program like Disk Warrior or Tech Tool Pro could do a better job. To use Disk Warrior, you would need to boot it from an external device, which probably means you would need a backup. For Tech Tool Pro, you can run it from its "isolated" edrive located on your boot drive.
Also, if you have two Macs, you could try and do what I earlier suggested, connecting the problematic imac to a working Mac in Target Disk Mode, and then try and repair the disk on the iMac. One thing that could work is to rebuild the directory. Not sure if Disk Utility either does that or does an "acceptable" job, but Disk Warrior is excellent for that, and secondly Tech Tool Pro is good also.
When you get your successful regular boots, are all your peripherals connected? If they are, then you might try, after the safe mode process again, to run your machine and leaving the peripherals disconnected. If you keep getting good results, then there could be a problem with the patch and one or more of your peripherals. You would then need to check them one by one to try and isolate the problem. If you don't get good results even after leaving all the peripherals disconnected, then I am out of suggestions (assuming you do not have a backup, discussed below, or not using a more robust program like Disk Warrior or Tech Tool Pro), beyond wiping the dive clean, installing Mavericks, and then installing all your software
The best way to resolve this is if you have a backup that you made prior to applying the patch. Do you have a backup? If you do, then one done via either Carbon Copy Cloner or SuperDuper! would be fantastic, as you could boot from that backup, wipe the drive clean on your iMac, and then do a restore from that backup to the iMac. I had to do exactly that for my Mac Mini about two months ago, as I developed a strange internet-related behavior for one site only after downloading and installing a piece of software (I was trying to help someone). Fortunately, that issue happened only two days after I did my weekly SuperDuper! backups, and my Mac Mini was back in business after only an hour of doing what I stated: booted from the SuperDuper! backup from one of my external drives, use Disk Utility from that backup to wipe the drive completely clean on the Mac Mini, did a restore from that SuperDuper! backup to the Mac Mini. and finally rebooted the Mac Mini. It has been running smoothly ever since!