1+ On not bowing the neck. You should keep the neck flat or at no-tension until you have strings on. Adjusting the truss rod should be done VERY carefully and only to get the neck flat if it does not have strings on.
1+ on the straight edge resting on the saddles. It may be fine, but I'd want a bit more downward adjustment. A mm or two. You have lots of adjustment up. It's adjustment down that you need to worry about most.
1+ On shimming rather than sanding if at all possible. Sanding to create an angle risks putting a curve in By contrast you can shim by creating steps with veneer and still get lots of surface for the glue to stick to.