As someone who's spent a good bit of time this weekend doing my own radius arm bushes, nothing to be scared of! I was putting it off but its not too bad a job, the biggest issue I've had was getting the offside arm off. I had to cut the front bolt and the big nut needed a lot of back and forth with a breaker bar to get off. After that I was going for method of drilling out the rubber/centre, cut the outer with a recip saw and chisel out. Then fitted poly bushes. Putting them back on I still have one to do tomorrow morning but I didn't even jack anything up, just using a ratchet strap to move the axle to get the first arm back on, and ill do that for the other too.
As for the hub seals, as previous comments say depends what is actually leaking oil. I've had a couple of drive flanges leaking oil, just stuck a new gasket on and made sure the axle breather was clear to make sure there's no excess pressure forcing oil out.