Here are a few tips tricks and quirks, I'm sure this will end up far more comprehensive ...
Substitute n|y for add|rem.
Most commands take a boolean option to enable or disable a certain viewer behaviour. As far as RLVa (and Marine's RLV) is concerned add=n and rem=y. The following commands are functionally identical, the latter saves you 2 bytes of script memory. If you're calling a lot of commands this can add up quickly.