Winterization

David, 3-7 are great ideas.  Funny that you leave the alarm covers dangling, I did that last year for the same reason.

However, I recommend charging the battery fully and leaving it outside or somewhere else where it will stay cold.  One of the interesting properties of lead acid batteries is their life is extended when they are kept cold (and it is reduced sitting in the hot sun in the summer).  Also, their self-discharge rate is reduced when they are cold so you don't have to charge them as often.  In the summer you need to recharge at least once a month, but in the winter - if the battery is left where it will stay cold - you only need to recharge every couple of months.

You may also wish to store your Pod wheels on a some strips of plastic vinyl.  A friend of mine in the tire business stated that the second worst environmental effect on tires (after UV-sunlight) was allowing long-term moisture contact under rubber tires.  Even a concrete floor will transfer moisture up to the tires if it can.  I store my Pod in a concrete floored machine shed.  The concrete was 'sealed' and cured for four years.  I accidentally left a piece of plastic sheeting on the floor.  After about a month of fall storage, I picked up the plastic and found water actually dripping from the bottom.
I believe that letting the Pod tires sit directly on gravel, dirt, or grass would be even worse.
From that time on, I have made it a habit to make certain that all of my trailer tires have a vinyl strip under the wheels.

I wanted to be able to get at the RV antifreeze pickup hose easily. After removing the hold-down screws on the seat base above the pump...I installed a couple of flush brass hinges along the wall side of the seat base.  I also drilled a hole on the inboard side of the seat base so that I would have a 'finger hole' to lift the base up. The seat base sits on top of the surrounding structure, so there is no worry about the base falling in. 
(If you just permanently remove the hold down screws there is a chance for the seat base to shift
while you sit on it...you would do a lot of damage falling into the pump/heater/plumbing area!)

You must do more than the drains - the internals of the faucets will be destroyed if frozen.  My 2010 171 has the water pump back by the water heater.  You have to lift the mattress on the queen bed, then you'll see several screws holding down the plywood to your right (same side as the kitchen).  Unscrew them to find the water heater, bypass valves, water pump, and antifreeze hose.

on my 2009 rpod 171 the hose is attached about 6" from the water pump under the stove cabnet.  But i heard on some newer units they have moved the pump back with the hot water heater.  Mine is a clear hose that has a threaded end on it next to a shut off point.