You can convert to Gen 2 and install the rom directly using the TPT method in the Swedish Snow thread. If you want to be able to install ICS roms later, then you might want to use a different TPT to convert to Gen 2 and then flash Swedish Snow via recovery as the Swedish Snow TPT will not give you a big enough system partition for ICS.
The Gen 1 to Gen 2 TPTs which are used on TPT upgraded Gen 2 phones are Gen 1 style TPTs. You should pick the TPT upgraded Gen 2 option (although it actually doesn't matter as its just setting the type of TPT to use and its the same for both those options). It should be clearer in the next release.
It might take a few minutes to unzip, but if its taking longer than 5/10 mins, then that seems a bit strange. The files it needs are saved to your sdcard, so if there are already there it doesn't download them again. You could try deleting the TPT Helper folder from your sdcard to download it again in case something has been corrupted.
If you try and flash a stock Gen 2 TPT and your phone isn't that type, it should just not start. Its unlikely that it could brick it, but if you don't have that type of phone then there's no reason to try in case something does happen.