Sounds like normal stock operation to me. There's a reason why the turbo master came out. On mine the PCM would pull the boost just when you'd need it.
Do yourself a favor and buy an assortment of sizes of clear tubing. Makes diagnosis much easier and faster. I have a hard time believing you had trouble finding it. Home Depot, Lowe's, just about any small town hardware store carries it.
Another reason to use the clear line is that now you're getting ready to drop the tank. If you used the clear line you'd know if that is a wise time investment. If there are no bubbles going into the LP then there's no need to check further back. It's the ultimate diagnostic tool.
While the new fuel may be harder on the pump then the old fuel there wouldn't be very many db2s left on the road if it was drastic as that. Having said that IF you use the clear line there's no reason to take it for a test drive, just look at the hose while idling.
IIRC there's only two sections of rubber hose before the LP. The one at the LP and one longer one at the fuel tank. If you have a hole rusted through anywhere it's most likely coming out of the tank. I wouldn't even bother with the return side just yet. Also just because you replaced the LP a...
Most expensive part so far has been the pilings. I made the 8x8 beams from trees on my property. The 3x12s the floor is framed with a buddy of mine gave me from a bridge deck. The 1 1/8" plywood came off a job I demoed. Thinking about painting the floor with some rubber roof coating.