For the shrinkage.....
Hi I'm new here too, and I had the same problem so I spoke to my rep. I use Jessica gel, she advised to cure the nail for a few seconds after application. So now I gel one nail cure and whilst that's curing, gel the same nail on the other hand then cure and return to original hand. I do this to all 5 on each hand, when I have done that I gel the whole hand then cure then the other and cure. Hope this helps. Also make sure your first application is thin, second can be thicker and sometime you may need a third depending on the colour.
For the dust I always wipe over after buffing with alcohol to clean the dust away. Or Sometimes I use a brush to help remove dust too, like a big powder brush. And at the end of the application I quickly file the free edge to take off that rough edge.
Hope this helps