Well, it's practically impossible to leave a Galaxy S2 out of action. Even if you brick it, you can almost always enter into Download Mode (volume down+home+power). I've bricked my phone several times myself, totally recoverable
The idea of using Odin is that you forget about Kies, you can even install stock roms with Odin without rooting your phone. And regarding which rom, as long as it's a Galaxy S2 GT-i9100 rom you can try any of them, if it doesn't work as you want, you can always try another. Flashing roms is really funny

(always be sure to have a decent battery level, preferably full, that's important in case of a brick)
Now, for your problem, I'm not really sure, but it might be an issue with your codecs. Try connecting your phone first and then open Kies. Wait for everything to be installed and it should recognize it. If it still doesn't work, close Kies and turn off your phone, enter Download Mode (volume down+home+power), keep pressing the three buttons and when you see the logo of GS2 then release them at the same time. You'll see a warning message, press volume up to continue and you'll see a message saying "Downloading please don't disconnect..."
Connect your phone and wait for everything to be installed. Once done, reboot your pc and exit Download Mode (press the power button until your phone turns off), then turn on your phone normally and see now if Kies can recognize it (remember always connect your phone first and then open Kies).
Although, before doing all that, it also often fixes when you simply connect your phone in a different usb port

.. Be sure it's not a codec issue, no matter if you use Kies or Odin, the codecs are very important for both.