Yeah you have no clue.
1) 75mp is probably doable if you drum scan some black and white 5 ISO special snowflake film. I don't have to tell you how unpractical it is.
2) No, man, in the real world your figures are wrong. You will never get real "75mp" from 35mm film, it's just not in its scope, even if 1) happened, with all the money and technical limitations, it still wouldn't be 75mp.
3) again, anyone doing archival job that NEEDS high resolution is shooting digital, this should tell you that your argument for film sharpness is idiotic.
Film is still used because of the pleasing rendition of tones, organic grain instead of shitty noise, and dynamic range. Sharpness doesn't even factor in.
For all practical reasons, 35mm film once scanned, drum scanned or "dslr scanned" hopefully, but a flatbed can do good if in proper hands (see our nature guy, he did amazing scans) will yield 8 to 16 mp depending on film and conditions, with the average being 12/14mp.
But, AGAIN, it doesn't matter - 35mm film looks really good, resolution is not its strong point anymore, the limitations to achieve high resolution on 35mm film are just not worth it, and hardly compete with a modern full frame camera.
And in any case, there's 6x7 to easily wave your dick over digital full frame if you need resolution.