Those two drain tubes under your FW tank are indeed the overflows, and water will run out when the tank is overfilled. That is normal. As for the low point drain leak, is it coming out of the drain hose, or coming out around it ? If coming out the hose, you probably have a leaking valve up inside the trailer. If around, then you probably have a leaking joint somewhere above the drain hose, or a cracked line or fitting. Neither one is normal. You will most likely have to get up under the trailer, and maybe remove an underbelly panel, to see where water is coming around the hose, and then trace it up into your cabin until you find the leak. If the valve is leaking, you might try opening and closing several times, in case there is some dirt or crud causing it to not close properly. If that doesn't work, a new valve is likely the solution.
2003 Ford F-350 V-10 Crew Cab 4WD Long Bed
2004 Jayco Designer Medallion 29 RLTS 5th wheel
Bill, Gayle, and Mindi (dachshund)
Retired at last !
Nothing is foolproof to a sufficiently talented fool.