Ford - Explorer :: 2001 - Small Leaks Coming From Transmission And Front Differential Gasket

I purchased my first truck 2 weeks ago private sale a 2001 Explorer Sport Trac 4v4 4.0L. I noticed it had small leaks coming from transmission and front differential gaskets (the diff is silicone) but the oil levels remain fine. Within days I heard a loud hum coming from the engine for 10 seconds then immediately after i was slowing down for a speed bump and my truck tried to stall and since that point it was riding very rough at low speed/idle and sometimes giving it gas seemed to just kill it. Next day a check engine light comes on and I get it checked It was Bank 1 running lean and B1155 (Output shaft speed signal) which concerned me from what I found it is located by the transmission oil filter which has the leak.

A few more days later I broke down on the side of the road, the alternator had died and killed the battery, I replaced the alternator and belt, replaced the 6 spark plugs, 3 of which i removed way to easily with my hands and all 6 had an incorrect gap. Initially the car was still rough but now with the new plugs it is drivable but still a little weird on startup and idle and a little bit of the shakes around 60-65mph and seems to be over actively shifting soon as i let off the gas even a little bit. Today I had the check engine light assessed again, now Bank 1 and Bank 2 are lean, still have the B1155 as well as a new C1676 (Battery pack voltage out of range) which light research said it could be ABS module or it could be a false code from being jumped days prior and that code wont clear on its own.