Also its important to know, I shot this film at ISO 400 by mistake and compensated for this by running -1 stop in the development process.
Well, that's a mistake for sure. But I assume you push processed, i.e. you developed longer than the standard 3m15 to compensate for the underexposure.
- The picture has high grain, what caused this and can I prevent it?
Superia 200 is a grainy film to begin with. Exposing and developing it correctly minimizes grain, but it'll remain fairly grainy in even a best case scenario.
- The negative has a strong offset to red and a fair bit to green, what did I do wrong? Possibly I didn't agitate the fixer enough?
You showed a digital scan, and that says virtually nothing about the negative other than that there is contrast and color. But so much happens in the scanning and editing process (with or without your being aware of it) that is makes little sense to draw conclusions about development from a digital scan. Your scan looks like a typical Superia image, which tends to be fairly contrasty and saturated to begin with. Likely in the digital process, contrast and saturation were enhanced a little further, either automatically or by you intentionally.
- When loading the film for development, I did this with bare/unprotected hands because it gives me a better feeling if I'm doing it correct. Would it be recommended to wear lint-free gloves? Do the oils on my fingers pose a realistic risk to the development?
Bare hands are just fine. Wash and dry them before loading film and you're fine.
Some after-development questions:
- The picture suffers from lots of little white spots, some of this is dust but some of it just won't come off with a little bit of air or 99% isopropyl. What did I do wrong when drying or storing the film? (This is a after-developement issue right? Or also a chemical issue?)
Hard to tell. I don't see all that much problems in that single image, but in general, causes for white marks on the positive image (print or scan) can result from:
* Dust sticking to the film after processing when it's still wet.
* Dust on the negative when scanning or printing; obviously you can wipe this off and make sure you work in a more or less dust free environment.
* Particle contamination of processing chemistry, particularly the fixer and final wash. When reusing fix (or blix), you may want to filter it before use to get most of the crud out.
- When cleaning films, what is recommended? How sensitive is the film to damage actually?
Don't. Just prevent the problem altogether. Any other approach will always be a compromise, a mess, may damage negatives and overall a chore. It's not all that difficult to make clean negatives.