You can go back and forth without issues, you just need an unlocked bootloader and you can flash the old factory 4.2.2 image or go custom if you want. I've personally had no issues with 4.3 but I did install it clean using the factory image as opposed to waiting on the OTA so it might be worth giving that a go first (although you'll obviously lose your data so back up anything on the 'SD card' before doing anything)
I'm not meaning to have a go, it's just that these toolkits cause more problems then they're worth! :)
And yes the link does mention what to do if you lose the memory on the device, mine did exactly that as well! :D
"Once they can be bothered to deal with the fallout in sorting out any problems, I don't think it matters one bit what method people use."
There lies the issue, users expect to be told how to fix something. If they were to post on here they might get help, but they'll get flamed to hell on XDA as there is SO much information available on there and Google that there is no excuse not to work it out for yourself. IMHO the toolkit is the worth thing to ever be invented as, like you said, people just click buttons and when something goes wrong they panic and usually do more bad than good trying to fix it themselves.
Learn adb/fastboot (takes all of 10 minutes to know the common commands to use with any Android device) and you'll never be a slave to a toolkit every again ;)
People really need to stop using toolkits and just learn to use adb/fastboot manually. It's so much easier to work out issues if you know what's going on in the first place...XDA has a very nice guide on everything here: