Hi Brad, more observations and advice (hope you don't mind).
Your #1 and #3 plug wires look kinda short, can't see the dissi side in the picture so it could just be the way the wires are ran.
Not sure what brand wires you are running, over the years I have tried many different brands of plug wire, Taylor 8mm, Excel 9mm, MSD low resistance and tons of factory replacement aftermarket wires. The best, most reliable, no issues, no bullshit wires you can run are the NGK blue factory replacement wires, on every F2T I ever owned no matter what fancy performance wires I ran (because of claims or color) the engines always ended up running used NGK blue wires I had kicking around.
The same with spark plugs, NGK V groove #7 (colder) or #6 (normal) spark plugs are the best plugs to run in these engines, I haven't tried as many different brands and types of plugs as I have wires on these engines because any time someone had an engine issue with an F2 and the plugs where different or new I would clean a set a set of old Vgrooves on the wire brush bench grinder, gap them and install them and the problem would go away. One 626lx auto we bought cheap, the guy did the air filter, plug wires, cap, rotor, plugs and oil service then the car wouldn't start in the rain or damp weather. I told him it had to be one or several of the new parts he put on that's causing the problem that wasn't there before, he said no those parts are new it must be something else. When we got the car to the shop I noticed he installed champion spark plugs so I threw them in the trash and installed 4 factory original (150+K miles) worn Vgrooves and the problem was solved so we sold the car.
If you look at my first picture in post #68 you will notice two black plastic clips that are screwed to the valve cover, these hold the spark plug wires to the valve cover and keep them from absorbing as much heat, melting or falling onto the manifold. If none came with the engine I might have a couple I can scrounge up at the shop.
The mazda part number is FE5010224, they are used on the mx3, mx6, 626, mpv, 323...
The screws are part number 99860-0512B
I spent a lot of time cleaning engine bolts for my 626GT build, I soaked them in apple cider vinegar to remove the rust, washed them and dried them, used eastwood degreaser/bolt blackening kit and diamond clear, they all rusted more than before I cleaned them. I have since been sand blasting them or cleaning them on the bench grinder and spraying them with Krylon (paint primer in one) matte black and matte clear spray paint, it's less work and actually lasts. Matte is thinner than gloss it doesn't effect the threading of bolts or pinch on the nut and bolt heads when torquing them, I had always been very careful to never get paint on threads but since working with the Krylon Matte spray paint and having no issues with up to 3coats (2black,1clear) I have been cleaning and coating the threads. 1 coat of gloss will gum up the threads and cause issues.
The very best thing you could use would be Cerakote, of all the fastener coatings available it seems to be many times more salt and chemical resistant and durable. But the cost and work involved using cerakote (even air cure) doesn't seem worth it, However I suspect that the instructions (or training) required to do a perfect job are to achieve perfect results. They state that to adhere properly parts must be blaster using 100% aluminum oxide or Garnet sand, these are both very expensive medias to sand blast with. Cerakote states in the technical data files that it has the highest adhesion rating possible (measure based on penetration depth of cross cut tape). So it would stand to reason that if the adhesion of POR15, powdercoat and spray paint is good to excellent when cleaning parts with a wire brush or affordable silica blast media than cerakote would adhere as well or better on the same metal finish.
Por15 has terrible adhesion and will only stick to properly prepped and etched metal surfaces, if you put the second coat on after the first coat cures (it cures fast in damp air) it's like painting it on plastic (won't stick to glass or plastic). Powdercoat can be used on new metal after only cleaning but doesn't adhere well, some spray paints can be used after simple degreasing and have good adhesion but have the weak finish and low chemical resistance of spray paint.
Eastwoods new blackening system has improved but is expensive and has a cure time of 3 to 4 weeks.