Rims and tire question

I just bought a set of new rims for my charger and I have a few questions hopefully you guys can answer for me. I probably should have asked these before buying them but too late now. Ok I have a 2010 charger sxt rally edition. Factory tires are 225/60/18, I bought a set of American Muscle 18" rims that are 10" in the back as 9" in the front with a decent offset, don't know the exact. They have Sumitomo 285/35/18 on the rear and 275/35/18 on the front, with a max load at 1521 and 1604 on the tires. I know these will throw my speedo off, I've planned for that I want to know if the tires can handle the weight of the car and if I'm going to have any rubbing or brake problems? I did put the front rim on the car and it seemed to roll and turn fine but had very little space between the inner rim and the caliper. Please let me know what you know. Also what would be the smallest width tire I could put on these re if I have to buy new tires?

Thanks