It looks like you may have a leaking oil pressure sending unit but It looks to me from the pics that the oil filter adapter is leaking . On the 4.0 litre , there is a hex shaped nut or a torx at the end of the adapter that unthreads from the block . Inside the adapter are 3 o-rings that should be replaced. These are typical and also cause oil pressure to drop some as well . I would say start there and see if and what still leaks before purchasing a sending unit . Some are pricey.
You must correct this leak before you cook that starter ! Something else to check is the vacuum control for the heater core hoses which is right above the starter . Drips from there can cook the starter too ! I would definately clean everything and check the crankcase breather as advised to make certain there is not excess crankcase pressure. While there is no PCV valve on the 4.0 , there is a crankcase vent system and should be checked. The valve cover is wet so yes , that is from pressure . The oil filter adapter and oil pressure sending unit are prime suspects but do not rule out excessive crankcase pressure. If it is wet around the dipstick , that may be contributing .