Water Sensors

Shouldn't be a problem. The 'liquid' that comes out of 'canned air' is actually compressed fluorocarbon gas - I'm not sure that will even trip the liquid submersion indicator in an MBP.

No.

Clarify which last part?

No, that's not a problem. I routinely use wet-wipes on my trackpad and keyboard. As long as you spray the cloth, not the computer, it's fine.

Where are the liquid sensors in the MacBook Pro's?

See this.

As was mentioned, any liquid/spray that is used on the exterior should be applied to a microfiber cloth and not sprayed/spilled on the aluminum. Liquids will "run" and you don't want that liquid to get under the keyboard or under the trackpad.

I use iKlear with a couple microfiber clothes to clean every inch of the MBP, from the plastic keys, to the glass, to the aluminum. It's safe for these materials (and says so on the bottle). The folks at the Apple store use it all the time. It's really the only thing I've been using for the last 3 years on both my MBPs.

You have nothing to worry about. Some people worry about high-humidity environments, rain, spilling liquids.... as long as you take precaution never to put that cup of coffee 2 inches from your MacBook and don't put it on the kitchen counter next to the sink, and you don't spray cleaners directly on the hardware, I would say you are 99.999999999% fine.

Bryan

Just be careful of using paper products to rub your finish. I've seen cases where paper towel actually left tiny scuffs/scratches. I'm sure tissue is down on the list of abrasive paper, but I'd rather be safe just the same. Also, tissue could come apart and make it's way under a key or somewhere you don't want paper to end up. Ideally, you'll want to use a soft, lint-free cloth, microfiber if you can.

Bryan

Please err on the side of caution and just use the iKlear kit! It includes everything you will need.