May I ask which individual told you this? Such a comment seems rather unwarranted since there is no logical reason to conclude North American phones have a greater chance to brick.
As long as you follow the same procedure, everything should work out. For a North American user, since none of these firmwares are from a North American source, you will definitely need to take a few steps after reflashing, such as setting up your APN from your NA provider, since they will likely not be available in the firmware you flash over (use something like APN backup and restore for this).
I am from Canada and my phone is Rogers (my service provider) branded. I really want to update my phone but when I go into the about screen on my phone the Model Number is: GT-I5700R. For people in the rest of the world isn't it GT-I5700? If I install a European firmware for example would everything work or would it be ok? If something doesn't work is there a way to go back to 1.5? Do I loose the crap that the service provider from who I bought the phone put on? Also is the installation process just the normal instalation process from Home