As a result of needing to replace a chainring ( Worn out chainring or missing tension ), I'm about to reinstall a crank, and would like to clean it before doing so.
Regarding the next picture, can I:
clean outer (1) with soap for dishes (rinse), and before installing it, apply a very fine layer of all-purpose grease (conforms DIN 51802, DIN 51825 part 2 and NLGI-class 2, made for long term greasing of motor and machine parts, specially for fast moving bearings)
clean inner (2) with rinse and scrub it with a plastic brush designed to clean drinking glasses, then apply very little grease to the thread
remove (3) the sealing ring, scrub the black, flat surface (update: I thougt this black surface was grease mixed with dirt, but no, it is clean black-painted metal) with rinse until it shines, then apply grease to it and put the seal ring on again.
apply (4) Loctite 243 to the screws of the smallest ring, since it originally was super hard to open and had this green stuff in it? Loctite 243 is red, apparently it can be used everywhere on the bike (I've never used it in my life and have a new one unopened). The outer and middle ring had no green stuff applied and were not hard to open.
Specially (3) is what worries me a bit, maybe it is better to leave it as-is
Next two pictures, what and how should I clean and grease something there? I've labeled parts for you to make easier references in the answer. The bike has a SM-BB52 bottom bracket.
I'm a bit embarrassed about the dirty frame.
What are things I absolutely should avoid doing?
I do have "chain cleaner spray", "break and parts cleaner spray" as well as isopropanol 99.9% at hand.