Pick a direction and go with it. Like someone said, there are too many chefs in the kitchen. To me, sort out one system at a time.

I can't see the pics, but, make sure it's a fuel issue or an oil issue.

An MP orange box will usually have 6-8 volts at the coil. If you hook up the MSD, the box controls voltage to your coil.

At this point I wouldn't worry one lick about what your total number is. Set the timing at idle to 20-22* and get the carb idle issues/settings sorted out. You have a pretty large cam at 237* @ .050 so it's not going to be as easy as a stock cammed deal.

I never saw an answer to running the idle mix screws in, does the engine die?

Does the idles speed screw have any effect on idle speed? If you back it out does the rpm drop.

Remove the carb and look at the transfer slots on both primary and secondary sides. If the primary side is shaped more like a rectangle, open the secondaries very slightly, maybe 1/4-1/2 turn and shut the primary side down. A trick if you don't want to remove the carb if you can get in there is put a .006-.010 shim between the secondary set screw and the shaft stop. It's likely buried under the vac sec mech. Then shut primary down slightly.

If you have power brakes, plug the fitting at the intake. Take it out of the system and anything else vacuum related to isolate your intake tract.

Might not hurt to lower the float level about 1/8 turn on each end.

IMO, 70 primary jets are not close to big in this carb.

Cleaning up fouled plugs is a band aid.