Those two lines from the FPR to each head that are swollen and cracked are your fuel return lines. Many have had theirs degrade. Get J30R9 fuel injection hose from any good auto parts store in 3/8" ID. It's a PITA replacing them and you'll need new fittings. Might as well replace all the hoses down there with J30R9 but some are 5/16" as well.
Ford sells the fuel bowl heater for just over $60. Mine is toast so I tossed it and am not going to replace mine for $60.
Many run theirs without it. Unless you live in a very cold climate where the diesel will gel and form wax IMO it's not needed assuming your glow plug system and block heater are working fine.
Common fuel leaks come from the sensors screwed in the fuel bowl especially the fuel restriction sensor. The two -202 o-rings on the drain valve should be upgraded to Viton for a one time fix. The hose clamps should also be checked and replaced with fuel injection hose clamps not the cheapo worm gear style.
If you really think after this tear down you won't be needing to monitor any fuel drips for a long while you're fooling yourself. This new formulated ULSD is killing our fuel pumps due to lack of lubricity. Do yourself a favor and add lubricity whether by using biodiesel or an aftermarket additive.
