Your chances of getting frozen from score sending are very very low as long as YOU ARE CAREFUL. I can't stress that enough. Make sure your scores are realistic according with your times. Taking a break helps too make it seem more legit when you're SSing for the AC. 300 YYB and 500 MSN games every day seems completely unrealistic so set reasonable break periods.
Your chances look pretty much like this:
-If you play it safe and triple check everything: Little to no chance of getting iced.
-If you just find some random SS list off the net and just use it immediately: You will end up getting iced sooner or later.