Yep, the OEM tires are junk AND the rear brake pads wear out faster than any other car I've owned.
However, they are ez to replace!!
There are FSM's here in the FAQ that give you all the torque specs that you need.
First of all, I'd get a tire tread gauge so that you can check for yourself.....2/32nd is legal, but I replace at 4/32nd.....and have replaced sooner on my kids cars....sold the old ones on craigslist.
Secondly, if money is an issue, then I would suggest getting some tools and performing your own maintenance....saving $$$ on maintenance is how I justify more tools!!!

Plus, you will know that it's done right.