About RAM, try to get at least 16GB
Switching Project between computers is not a problem as long as you have the same Plugins (and sounds) installed on both systems
Define "Smooth". That is relative, depending on the amount of tracks and types of Plugins you are using.
The limitations also depend on the specification of the individual computer: CPU, RAM, hard drive drive speed, screen size, graphics card (not so much). Main difference is probability.
Hope that helps
Edgar Rothermich - LogicProGEM.com
(Author of the "Graphically Enhanced Manuals")
http://DingDingMusic.com/Manuals/
'I may receive some form of compensation, financial or otherwise, from my recommendation or link.'