Not true(On both counts.). In the Dark Fleet Trilogy, Luke learns an ancient Fallanasi technique, which he can use to cut himself off from the Force instantly, and also restablish connection to it instantly aswell.
And the best thing Naga Sadow did, without the help of Dark Side Embued trinkets, was throw a small brick at Ludo Kressh's head. Seriously, people overpower the 'True Sith' wayyyyyy too much.
1. I meant Luke, too.
2. Note that create everything that gave Exar Kun and himself power.