I think I may know what you mean; every so often my rear brakes will get real grabby and try to lock up under light braking pressure. This only happens at very low speeds, like 5 mph or less. Usually it occurs in a parking lot or pulling up to a stop sign.
It doesn't happen often, but when it does it happens for several stops in a row. Then it will go away and not appear again for months.
In my case it may have something to do with the rear brake adjustment. My self-adjusters don't work consistently, and I've never noticed the grabby-ness after manually adjusting them.
So if by touchy, you mean grabby, and if it is coming from the rear brakes, then I would check the adjustment.
The other culprits could be particles of dirt in the brake line or cylinders that prevent hydraulic pressure from releasing, or perhaps a bad proportioning valve (if the rear brakes are grabbing).
Unless you've done it recently, I'd probably bleed the brake system to try to get rid of any dirt that may be in there.
Oh, and like Slave2theXJ said, the pulsing is probably warped or worn rotors on the front brakes.
Good luck- Robert