I think you may need a new glow plug. A little fuel/oil coming out of the silencer (muffler) is okay, indicates the engine is getting lubrication. The fuel line close to the head should be no problem, the fuel moves thru to fast to be terribly effected. The problem of the prime may indicated poor tank location in relationship to the engine. The tank center line should be pretty close to the same level as crankshaft, a half inch either way is okay. If too low it will be hard to prime, if too high will run rich all the time. Another source of hard to prime is an air leak like a hole in the fuel line, check carefully, they can break at odd spots.

There have been some reports of trash in the needle valve, take it out and blow out the carburetor. Use a fuel filter, some times there is unintentional trash in the tank.

Good luck,

Chip