When installing S/S screws , pretap the holes in aluminum and use a S/S specific anti-galling lubricant as S/S is suseptible to galling when used in bimetallic conditions. Whenever possible, use a torque screwdriver/ wrench and the proper values for the relevant thread sizes. Double check as to the torque values in the table you are using are dry or wet (lubricated) values.
PS . 3M makes various grades of threadlocker, removable, regular and permanet (never get apart without a blowtorch).