We have the exact same coach. I couldn't figure out how to turn that light on either and found it by mistake. Like Sbryant said, it comes on the "old school" way by turning the dimmer all the way to the brightest setting past the detent.
What went wrong with the refrigerator and microwave? It's odd that both went bad...had to be something major.
The audio/video system in our coach is junk. I will eventually upgrade the whole thing with better speakers, head unit, etc. I couldn't stand the extremely low sound quality of the bass so I upgraded that first. See my thread below for more info. On your video, it sounds like the video cable (RCA) that goes from the head unit to your TV is damaged or something. First, see if you can play with the settings to see if something is not right. If you want to verify the cable. Get a regular RCA cable (yellow, red/white) and hook it up behind the head unit to any TV....or have the dealer fix that also.
2014 Sub Radio Problems
Also, if you want better ride quality do the cheap handling fix and the rear trak bar. It's the best upgrade you can do to your coach.
I would also find out if all of your video options work (i.e. cable, antenna, aux). Ours were installed incorrectly and had all sorts of video issues which cause DW to be very upset...and when DW gets upset...well, let's not go there.
Yet another thing to check is to make sure your refrigerator works on batteries. On ours the inverter was never installed and had to contact FR directly to have them sent us one. Your refer will obviously work on shore or gen power, but while one the road you can depress the inverter power button (by the steps next to the batt disconnect, awning switch) and it will run on batteries. Another nice thing about that inverter is that it has two 110vac outputs. One goes to the refer, but you can use the other one for other 110 needs. I haven't done it yet, but I'm going to run an extension from the inverter to one of the inside outlets and mark it "inverter".
Good luck and let us know how it goes.