Need help with sluggish performance

Hiya,

SO I was working on a relatively small file, a skin prop for L'Homme, Renderosity's flagship figure.  I needed to create a foreskin texture and cobbled most of it together in Photoshop and then wanted to add more realism and what not to to it.  Well after adding a few layers SP slowed to a crawl and the update bar was taking forever so I deleted a couple of the layers.  Not sure what happened but I have a relatively good system.  So my question is are there work arounds to making things zippy when needed layers are needed for any paint project. 

When I loaded up the project I chose the 4096 resolution.  I THINK I remember that if I chose a lower resolution I could somehow update the entire thing to higher resolution when exporting and it would be high quality and crisp? 

Also for a program that touts similarities to Photoshop workflow I don't see some familiar brushes like blur.  I see smudge which has come in handy but no blur brush.  It would be nice to have the brush options expanded upon! 

Thanks so much

Richard (RAMWolff)