Ours keeps freezing also. At first I thought it was our system, but it was freezing so often that we couldn't manually save, select/check our team, buy things, or load the game when we first start it. I'm hoping they come up with a patch or something
Well, if you get a character in multiplayer to level 20, you can "promote" them to the single player game, which gives you more points towards your war assets. But, that also resets that character to level 1 again. And funny you should mention freezing, but I did freeze 3 times in a row just now...I was going from Presidium Commons to the the docks, and it froze each time. I had to go to another floor, and then to the docks to actually get there. Pain in the butt. T_T
Yeah, I did start the story finally, and got some of the DLC along with it. I didn't realize that multiplayer affects single player though, so now I have to juggle two modes at once. The story is pretty nice actually, I think it's a step up from ME2.