Getting a used Rpod, major things to inspect?

First time poster here. 

I am finally getting close to buying a 2016 Rpod 178 from some one, and would like to inspect it myself. The seller is retired and seems genuine.

The Rpod has been winterized and stored outside (sub-zero Celsius temp as it’s in Alberta Canada), and seller has agreed to tow it to my place since I don’t have everything set up with my SUV yet. I understand this is not the ideal situation to buy a used trailer privately since there are many things I won't be able to test out but to trust the seller, such as water heater etc. 

I am a DIYer and look after many things around the house and for the car, so I won’t be caring about small things too much, but still I want to make sure the Rpod is in good condition overall, and here is a list of things I have in mind: 

Externally:

1) Storage area water damage, gonna (feel it personally and use a moisture detector). 

2) Roof from a ladder, and also underbelly, check for any potential side wall and panel separation? 

3) Window and door seals 

4) Stabilizer jack and hitch etc. 

5) Slide-out (seller did disclose a push from outside might be needed to retract)

6) Signal lights

7) Rim, tires and brakes

Internally

8) Furnace and AC (not sure if can be tested in cold winter here)

9) Sink and toilet. (pour water down the sink and toilet to see if any leaks, will refill with anti-freeze afterwards)

10) Fridge (propane and shore power)/Stove/Microwave

11) Lights, outlets etc. 

12) Ceiling and floor water damage

13) TV and stereo (low priority, don't care much)

14) cabinets and beds. (again low priority if easy fix)

Do you guys have any suggestions? 

Thanks a lot.