2000 Grand Caravan No Rear Turn Signals or Flashers, NO REAR BRAKE LIGHTS!!

We were gifted a 2000 Grand Caravan which had some electrical issues (more on them
below as they may help illuminate what's going on now).
The heading sums up the latest baddest problem.
My wife came home, telling me that someone behind her honked and yelled while she
was slowing to turn at our street.
I started basic checking and found that both left & right rear turn signals work, but the
fronts are ok. I have no rear emergency flashers, but the fronts are working.
Worst of all, she has NONE of the 3 rear brake lights working.

The rear running lights do come on when I turn on the headlights, but nothing else.
Inside the cabin, I hear the ticking of what sounds like a flasher relay.
I'm clueless when it comes to this vehicle as I've owned only Subarus since 1988.
I googled my issue and saw posts about a combination relay/switch that is supposed
to be near the fuse box under the dash. I have pretty severe neck arthritis, so if I'm
going to get under there to look for it, I really need to know exactly what I'm looking for.
A picture of the combination relay (if that's what is suspected) would be helpful, if
anyone has one.

The other electrical issues are as follows (maybe they're related, maybe not). The
passenger door window and the passenger side rear vent window (electric) both don't
work.  I tried a basic test I read online where I turned on the headlights, high-beams,
and the blower (to stress the battery a bit), then tried the switch on the driver's door
and the switch on the passenger's door. No slight dimming of the dash lights, which is
supposed to point towards a relay issue, rather than both the motors being bad. Makes
sense to me. Also, the intermittent wiper doesn't work, only full-fast on, or off. That to
me, sounds like the 'rotating switch' at the stem being dirty corroded etc, but I don't
know how to get inside it to try cleaning it, before having to replace the entire switch.

We're re-gifting the van to our niece, and the window/vent issue is a pain, the wiper
issue is annoying, but I HAVE to solve the lights, obviously, AND FAST.