My view: I use contract freeze because the only one suffering is EA. I also only use the add goals in single players. In any game with both Online and Offline modes i hate the guys using cheats in Multiplayer. The rewards in single player are more or less the same as in multiplayer. Why shouldn't you just stick with using trainers in single player mode and use multiplayer to actually play. You mess up the whole game while you can get the same coins in single player. Apart from that, people will report you in multiplayer. Of course, it's EA, but there have been players banned. Why risk that. Even if you use a 2nd account, it's not like they can't trace where all the coins and players go to.
It's your own choise to cheat in Multiplayer but i really hope the ones that do get banned! We are here to play football, not to wait for half an hour to finally match someone that wants to play too. DIvision 1 and 2 are unplayable. Your mothers will be proud of you.