CO detectors don't always go off if you start having some exhaust leakage into the home either.

Is there any sign of leakage?

If you install a second peace of plywood or particle board on top of the first one.angle it out and then cover the surface with lino etc as instructed any water leakage will run out and the tenant will become aware that the sink is leaking before the cabinet rots.

Is this signs of roof leakage, and if it is how easy is this to fix?

Signs of leakage?

Call local utility company for leakage tests.  

And I don't like the leakage involved with the sale of my house.2) Hold current house and use equity to buy 2 SFR or a single MFR REI, outside the state where my dollar will get me properties that will cash flow more readily than here in Portland.

Even if you remove the tank make sure you get a soil test to ensure no leakage.  

We received some heavy rainfall this past winter, and now I have leakage around my chimney.  

Basic typically includes the following: Fire, Lightning, Explosion, Wind/Hail (but not Named Storm/Hurricane), Smoke, Aircraft and Vehicles, Riot or Civil Commotion, Volcanic Action, Sprinkler Leakage, Sinkhole Collapse, Vandalism/Malicious Mischief.The DP3 is also known as Special Form and that gives you coverage for any physical losses not specifically excluded in the policy.