When collecting maximum restraint loads search all load cases that might actualy load your system. Be sure to check both +tive & -tive.

Using your first example (without a LC1), I would add the following two load cases:
LCn: L2,L3,L4,L5,L6,L7,L8,L9,L10 (SIGN MAX)
LCm: L2,L3,L4,L5,L6,L7,L8,L9,L10 (SIGN MIN)

But you probably want to add a few more cases such as W+T1+P1-U1, where your uniform (seismic) load is in the opposite direction.