New to supras, got some questions.

[MA70-3.0GT]

Hmm, could be you were seen coming as they say, a mile off...
That said though if the no heater thing really is just the vsv then the rest could be pretty easy too. I'd suspect the head gasket really though knowing these motors. The way to check would be to find the vsv (top of engine bulkhead, with heater hose running to and from and vac pipe on top) and first disconnect the linkage on the bottom and push the lever all the way up. This should result in permanently hot heater amd would be good news for your wallet. If no heat still i'd stop driving until youve read up on air locks and "bhg" symptoms.

Ive also found a source of water leakage to be the spoiler gaskets/seals where it mounts to the tailgate. Probably bailed 2gal out of my 1/4 panels, algae included... least it proves theyre solid!!

Best of luck & fingers crossed we have a duff heater vsv...