Hi, I have a friend who lives in turgetries which is just outside Bodrum,and she once came to see me in Kusadasi by bus..so yes you can get there! It did take several hours though and I do recall her saying it was a bumpy ride!
I think it wont take more then 3hours. At least when u take the bus from Bodrum airport til Kus, it takes around 2-2,5hours. But when u take a normal bus it will take a little more bcause it it stopping on some places along the road to pick up passengers, or set them off.