Drywall – How to do after mistakenly using moldy paint on drywall

The paint/primer should be fine, especially with two coats, but I typically begin with primer, as it seems (in my experience) that primer holds paint better and lasts a bit longer before requiring touch ups or repainting, and it's often cheaper to do a coat of good primer (match latex to latex, or make sure you follow the label if you use a different combo), then two or three even coats of less-expensive paint (paint+primer is almost always 2-3x more expensive than paint alone.

I wouldn't sand and re-paint, of course. You should be fine with what you have so far.

[Edit: one other note on paint+primer paints; make sure you read reviews or ask others about their experiences with the particular brand you're buying. A friend ended up with a patchy-looking paint job when he used one of the cheaper brands. I don't know if it was an isolated incident or if the brand is normally bad (or if he didn't mix the paint well!), but research before you buy.]

There are different formulations for aluminum roof coatings. I doubt that what I'm about to say is incorrect, but if you want to be 100% sure, call the manufacturer.

Diesel contains surfactants and oils; diesel will leave a residue; I very much doubt that there would be any chemcial reactions, but it will probably result in wasted or reduced quality paint. You should be able to add a little (like 10% by volume) paint thinner if you need to store it (so that it doesn't dry out) until you have a chance use it. For recycling the aluminum (and probably perlite) sludge, the best advice (IMHO) would be to mix it with more/fresh aluminum paint, and re-coat this heavy mixture over the area that you painted with light-aluminum paint.