Move Part w/Physical Dynamics allowing Parts to pull through.

Move Part w/Physical Dynamics allowing Parts to pull through.  Isn't it supposed to treat any Part features as 100% hard solid?   I'm running Intel i5 2.40Ghz w/8 Gigs of Ram  on Acer Aspire 5 "gaming laptop" (was about \$700 two years ago, same exact currently sell on Amazon for about \$780).  Is that enough or is that my problem?

Anyway to tell SW to 'just take your time' and stop if need be to allow parts to touch but still move and slide against each other.  I'm doing pretty simple Assembly.   And what does the Sensitivity slide bar control?