Alright if you are cycling a tank, then first off you will not need the skimmer unless you are curing your liverock in the tank then use the skimmer. Leave the lights off for a few more weeks or for just a few hours a day. I do not see anything about power heads or your turnover rate, so I think maybe you could use the extra circulation of the canister.
I would not leave it off and only start it a couple of times a day, someone may say I'm wrong here but letting your water in the canister sit might start an anerobic reaction and then by turning it on and desturbing that might not be such a good idea, a guess on my part.
On my 90 I personally did not run any carbon until the cycle was over, a 40 gallon water change, and I started to feed a couple of chromis fish, and was well into a diatom bloom, then I added a batch of carbon to the system, and the water became noticably clearer.
If it were me, I would run your canister, at the very least for added water circulation. When you start adding fish and a cleanup crew for the diatoms, then I would add the carbon. It will be a while before my 90 is stable and until then I will run carbon, I have run carbon for years on my 55, both reef tanks.
Others only run carbon for a couple of hours a week. Here are a couple of links on carbon, you decide on how you will use it.
http://www.aquarticles.com/articles/...%20carbon.html
http://www.hallman.org/filter/gac.html
Thomas