Never realized so many having problems with Kies. Truth, I don't really like Kies. Its actually way to slow. If not for the fact that I need it for firmware upgrades (Officially), and backup of contacts, memo, notes etc., I probably won't be using it at all.
Transferring files (to back them up), is so much faster by going into USB mode and connecting like that so that the phone works like a external HD. Simpler too.
So far though, I noticed that Kies is more stable on Windows XP Pro. I am using Windows 7 64bit as well, but when using it with kies, it ran into some issues. I also noticed that if your internet connection is not stable or fast enough, the firmware updates can stop midway. I use XP in the office and the internet connection there is faster, and that could be the reason I have less issues with Kies using XP.
That said, I never had to do any debugging for the USB connecting to Kies. I downloaded the Kies of the net, installed it and then everytime I plug in the cable to the computer, it will just go straight to the MTP screen. That's when I usually press the home button.
But if I want to use Kies, I usually switch it on first before connecting the USB cable. Sometimes the connection do seems to get stuck, so I usually just restart my phone and the computer and eventually they do connect. Never had a case where just cannot connect at all (Yet?).
Cheers and sorry if can't really help since never had all the problems described or had to go through all the debugging steps.