Nathan
There are two issues here: rendering performance (the time it takes to draw it) and logic performance (the time it takes to process events, collisions etc. for the object). Invisible objects, or objects on invisible layers, don't take any rendering time, but their logic performance is unaffected - events obviously keep running for invisible objects!
Trying to change your events to make it faster is usually pointless: I doubt you can measure any improvement at all changing your events to improve logic performance. Game performance is usually 90% the rendering performance.
As for size/position/angle: the short answer is no, it doesn't affect performance. The long answer is it can if the rendering is software rendered, but usually software rendered platforms are not particularly usable anyway (they're too slow overall). On hardware-accelerated systems it makes no difference at all.