little help with the AB!

MM Acryl is notorious for tip dry. Get some Liquidtex or Createx Acrylic retarder and put a drop into the thinner you use, then add to the paint. Should put an end to tip dry.

Just in case though, keep a little cap of Windex and a Qtip handy. When not spraying, swab out the regulator (pull the needle back first) and tip dry should be nothing but a bad memory.

You can dump the paint down the drain, that's the nice thing about acrylics. Soap and water wash up your hands.

Tip dry is a way of life with acrylics and while using retarders and so forth helps there is not much you can do to eliminate it IMHO.

I suggest you become used to picking the paint off the needle tip with your thumb and fingernails as T-shirt artists do all the time. It keeps the needle fairly clean and allows the paint to flow better.