interior conversion

You do NOT want a tub, just think of all the water it takes to fill it and how that will effect list when it is full, plus nobody ever uses them. You could make the 2nd head into a large shower only. But it's really nice to have 2 toilets on a liveaboard in case 1 doesn't work.

No, No tub.
Get a cattle feed water tub and put it on the dock if you need a red-neck hot tub.

On our past 34, we had a wet head/shower. I called it my vertical bidet.
All was good. Exhaust fan out, A/C inlet in.

On our present 58, still have a similar wet head forward but rarely used unless I had to many hot peppers the earlier evening.

If you have the real-estate, a real nice shower in a wet-head config. Good place to sit while scrubbing your toes and a back-up head.
Then a nice master head.

Sharp & fresh chain saw helps. ☺☺

But chain saws are more fun.
Make a lot of noise and smoke.

Brother, Are you loosing your sense of adventure?
Already major blood loss?

Rip er up !!
Most fingers can be super-glued back on..

Something I'm just remembering; On mine and another Bertram's interior mods, the bulkhead (separating wall) tops were not fastened to the overhead.
The bottoms were a part of the deck, most side edges were tab's to the hull, but anything above the gunnel fitted into overhead slots.
Once the shoe box top (cap deck) was lowered with headliner, lights and wires already installed, all else fit into place like Lincoln Logs.