[rockyfeller]

It's hard to tell 100% but most probably those cuts in your tire were due to fender rubbing. You should have heard some noises in the cabin when the tires rubbed especially on full compression. The easiest way to tell if the tires rubbed? Why not bend down, look up inside the wheel well with a flashlight and look for evidence of a rub at the fender?

The main cause is not weight, but because you're running aftermarket wheels that have an aggressive offset and the tires are coming out of the fender.

From the pics you provided it looks most likely like the car is safe to drive. The cuts in the tire are fairly superficial and within the tire tread. They'll wear through. The real danger is when there's a full-thickness cut into the tire past the tread, then you'd need to be worried.

The only way to fix this is to change your wheels.