The Reynolds ride off stand will use the stock BMW bushings and bolts but uses different springs. Might find springs that work at hardware store but I don't know. I'm looking myself.
The side stand is not stock. The bracket for the original may be broken or missing. You might want to keep that one till you find out what you need to get something that looks and works better. Brown side stands look better. They are not stock but most riders don't like the OEM side stand anyway.
I just looked again at photo and notice you also have the stock sidestand.
Switches can be taken apart if you are a minute detail guy. Needs more natural talent than directions. And if you don't need a new one now you might need a new one before you're done but you might as well give it a shot. I've been missing the tiny detent balls in my switches for over ten years because I took mine apart. Half a brain and you should be OK.
That is an after market temp sender to read the temperature of the engine oil. If it doesn't leak you can just leave it alone.
Never memorize something you can look up.