Mirrored icons is your fault, you didn't select proper installation method.
As for the antivir/firewall issue, well I don't experience such issues, but it all depends what software do you use. Only advise I can give you is to add installer and world of tanks to exceptions/white list, and check other options there, especialy huge overdone software like Norton likes to block stuff here and there, gl.
Also get new modpack.No need to bump