1996 ford E150 5.8L efi, starts ok, idle iffy, wobbly belt tensioner

I live in pittsburgh, pa, I'm 65yrs old, i'm in the community of brookline, in the south hills. Most of my life i was a letter carrier, and very little experience tearing apart an engine,
Since mid june 2020, I have been tearing apart my engine on a 1996 Ford E150 5.8L EFI ,

took the van for a test drive today, for the first time, after making sure the idle was ok, and everything else was ok, well i couldn't get any power to climb a short hill. Engine didn't stall, it didn't have any acceleration as i pressed the on the gas pedal. Anyone know why? In park, i was able to rev up the engine, (in gear, no acceleration or power),

I have the van home now, the van starts fine, idle is iffy, till i turn the ac on, the engine will rev up, rpm's(i don't have a guage , i don't know, I never set the timing after installing a new distributor, I just placed it in as close to the same spot of the old distributor.
on level street, it accelerates and moves just fine, but no power to move up a hill, why?
Every day I start the engine, it starts up and idles better than the day before!
Today 08/03/2020 van starts ok, idle is fine, oil is clear, coolant level still the same after a week of running engine, since on july 5th I had first started van forcing it idle after putting engine back together with all clean parts, and had a coolant leak inside the intake manifold and coolant mixed with oil in the oil pan, which i drained a gallon of coolant and a few qts of creamy coffee colored oil

Today 8/5/2020 the idle is worse than ever, the belt tensioner makes noise, and wobbles way too much for some reason. this van cost $2500 to buy in oct 2019, and since then I have put another $6,000 into parts and tools included. and lots my own labor. $3500 to have the transmission rebuilt.
I'm ready to just give up, because instead of fixing i might have ruined the engine, maybe the catalytic convertor, maybe the pistons or rings, maybe the valves, idkk. maybe its just out of timing, I don't know

I'm thinking of for a 3rd time, removing the upper intake plenum and passenger side valve cover to check rocker arms and rods, check visibly the condition and movement, There does seem to be noise coming from under that valve cover, or should I work on setting the timing? I did a compression test,, no.1 is 126 no. 2 is 126, no.3 is 126, no.4 is 145/ not sure what those numbers mean.....if its good or bad? maybe I should do a wet test, with a bit of oil

Some before and after pics

removed reply

Just attempted to start the van today, Monday July 27th, 2020. It started without the issues I had after the oil got extremely hot yesterday(Sunday)and the engine could barely stay idling. Now it idles but there is some ever so slightly ups and downs in the idle, no issue in wanting to stall. And currently no check engine codes.
because the oil is extremely hot, after running the engine for a few minutes, it might be because there is air pockets in the coolant system, and maybe bleeding the air out of the system is all i have to do

I would say test your tps sensor and map sensor on firewall. See if there is any glitches or voltage dropouts. With the map sensor you will need to read the signal in hertz while useing a hand vacuum pump with gauge.

thanks for the reply
I will have to learn how to check those sensors, and what tools I would need to do those tests

Just a digital multimeter that can read hertz frequency (lowes, farm and fleet) , a couple small alligator clips(walmart automotive/ele trical isle) and some t pins (clothing store/walmart sewing isle)

Also wouldnt hurt to check base timing with a timing light.