On average, we believe the truss roof system saves about 30% compared to a standard post and beam construction.

Cheaper and faster, so, yes, better. In our opinion.

Yes, but always check with a Structural Engineer.

Uplift on the ends.

Most issues with trusses are the result of engineering to the bare minimum to save a few dollars on manufacturing.

Tail ends lift up off the exterior wall. From twisting lumber to extreme wind or down pressure in the middle pushing up the ends.

Solution? Hurricane clips.

None. Each truss is designed to take a load in a specific way. If someone removes a section, they remove its strength.

No and it's not usually necessary.

Sheeting is too light i.e. 3/8 Sheeting, or 1/2 inch Sheeting on trusses that are 24" on center.

Short answer, yes. Long answer, do these used trusses have engineering you could show an inspector? It might be safer to start fresh.