The Million Dollar Kitty - Ideas?

Sometimes I wish I had "normal" cats, but then I remember that most cats aren't normal - at least from the human point of view.

Anywho - backstory. Jan 2008 I adopted an "unadoptable" kitty from the shelter - senior boy who had suspected ringworm (ended up being a bedsore from sleeping in his litterbox). I named him The Chairman Squishy Meow - know to "commoners" as Squishy. He was estimated to be about 15ish, maybe 18 years old.

He then developed chronic urinary issues - he sprayed - we put him on S/D in case there were crystals, he was pretty much peeing red/blood so they couldn't tell for sure if there were crystals on not. We did multiple x-rays. after a lot of vet visits & anti-biotics, he was given the all clear.

He is now on C/D & Purina ONE urinary mixed (3/4 C/D & 1/4 ONE). *knock on wood* we've been clear of any problems so long as he stays on the C/D - if he doesn't he's back to pissing blood. He is an outdoor/farm cat - he lives primarily in an enclosure attached to a shed.

Had him to the vet today, we've been battling ear issues. Panalog for an ear infection cleared it up, but only for a short time.
~We got a new ear ointment to try for 10-14 days.
~We found what is suspected to be a BB under his front right leg (in his "arm pit"). Probably from before I got him, he was picked up as a stray when he wound up at the shelter.
~He also needs a dental.
~Oh & his heart murmur is now a Grade 3.

Before we do a dental/put him under anesthesia, we need get this ear infection cleared.

If this new ointment doesn't work - what else can I try? I've considered the food aspect being an impact on him having ear infections, but I can't switch him off the C/D.

Is there anything I can do to lessen the risks of anesthesia for a dental when he has a heart murmur? (Doing pre-op bloodwork for sure due to his age).

How important would it be to remove the BB from under his arm? I'm concerned about how well an incision there would heal, but also concerned about the additional time he would have to be under anesthesia.

Here's a picture of my baby boy

I bounced these questions at my vet, but was seeking outside ideas/opinions to make sure I cover my bases.

I dug back through paperwork, the BB was noted under his leg when he was at the shelter. So it has been there for awhile. It doesn't seem to bother him, so I will talk to the vet again when he goes for a dental to decide to remove it or not. I'm mostly a bit worried about "what if it isn't a BB?". So I may end up removing it for piece of mind.

He doesn't need a dental right now - they aren't that bad, but the vet said ideally within 2-4 months he should have one done. I think thyroid is a separate test than the senior blood panel, I might have the vet run a thyroid test also. They checked back on his records, he had a Grade 2 heart murmur back in Jan 08.

otto - will check with the vet about Tresaderm if this ear ointment doesn't work. I'm hoping it does the trick.