A few questions regarding equipment

[Ruth]

I don't think you can over skim either. You can go over kill - guilty - but not over skim. If you have a skimmer that is capable of keeping up with your system and put a bigger - over kill - skimmer on it a bigger skimmer is just going to get the job done a lot faster. There is only so much to skim. That being said the bigger skimmer will also get things done quickly if you happen to over feed - increase your bioload - or have a problem like something dieing in your tank.
Personally I like the insurance.
JMO