well not with a Droid 4 but with my Samsung stratosphere which is a 4G phone for verizon, i would use PDAnet and connect it by USB. i use about 15-25gigs a month and i have never had any problems. i don't torrent with my phone but i use it to download my PSN games that i buy from the store and also use it for online games like Swtor and WoW as my home internet is very very slow compared to my 4G speeds i get.
but also i do all my heavy tether use during late night (12AM-6AM) i never got throttled or anything before.
i used Fox Fi for my wireless tether app but lately i been having problems with it and it kicks me off 4G and i have to restart my phone but that is only for wireless tether