Hi, I plan on purchasing the S2 on Weds. I don't have ANY internet plan AT ALL. So any internet use is either going to be at home or any free wifi. So my question is if I use my home internet (wifi) will Tmobile still charge me? And since the S2 constantly updates, wouldn't that affect my bill? and is there a way to turn off all updating until I get on wifi? I just want to use wifi ONLY not the 3G/4G. Thanks so much!