In that area, a half bath adds $50k of value (mission beach).  

The easiest thing to do is have a plumber open the ceiling beneath you to diagnose.

Bigger Pocket is a very good platform to find people to help you. if you have half a million lying around, then I would say spend some money for these courses. 

IF my income got cut in half, the first thing I would do is cut my expenses by a whole bunch.

It's easiest to have the tile company do this at your initial closing, but you can do it yourself.

Even if you sell at exactly the same price you paid, costs will eat up half of my down payment.Maybe you can find someone willing to give you the money on these terms. 

Depending on location or even not, it sounds easiest to find a lender who would possibly cross/wrap enough of your other properties to get what equity is necessary to take down the new B&B purchases.  

All of these are within a half-hour's drive or slightly more. 

Have had to witness that first hand and work through a half a dozen of my land projects were I was the lead and the GP's stopped communicating leaving it to me..

It took over a year to get half of the premium advertised to us.