AF,
I have about 80 hours on the PA18, and of all the tail-draggers I've flown (PA18, Great Lakes, Pitts S2C and Europa mono-wheel) I found it by far the easiest. But I also have far more time on it than any of the others, so that may not be a fair comparison.
The most important thing for 3-pointers is that the stick must be all the way back - none of this set-the-attitude-and-hold-it stuff, you're going for a full-stall landing, or as close as possible. As with any 3-pointer, setting the correct speed over the threshold will make this easier, as you'll spend less time in the flare.
If you're bouncing wheel-landings, the only solution is practice - you have to recognise when the wheels are going to touch, and be ready to let the stick go slightly forward. The only way to do this is practice, practice, practice.
The swing is more of a problem. You really shouldn't need to use the brakes for directional control on the runway. There is nothing specific about the PA18 in this respect, as far as I know. One technique, for all tail-draggers, is the old cliche of dancing on the rudder pedals. I never really understood this until one instructor explained it as follows: use the rudders all the way to touch-down, even if you don't think you need to use them, keep using them anyway. Then, when you touch the ground, your brain already knows exactly how much response it can get out of the rudders, so there won't be the usual over-correcting which quite often happens.
If you're not doing wheel-landings, I suggest you get an good tail-dragger instructor and learn them. One common teaching technique for wheel-landings is fast-taxying, which will also teach you to control the swing. Apart from controlling the swing, and giving you more tools to use, learning wheel-landings will also help your general technique, for example you'll be better at controlling the aircraft during take-off especially once the tail-wheel is off the ground.
The only other thing I can suggest is to try a different PA18. I've flown 3 PA18s, and each one handles subtley differently, especially at low speeds and on the ground. If you try another one and find it easier, then there may be a problem with your particular aircraft. This wouldn't surprise me, especially what you said about not having the rudder authority to control the swing.
I agree, by the way - the PA18 is the favourite of all the aircraft I've flown so far!
FFF
---------------