While the nut is questionable they do serve a purpose, to prevent valve stem rattle. But a bit of tape can get around that issue.

For the caps it's just pointless. They put them on there to protect the tube when they package them. The they do not contain a seal like automotive caps so they server no purpose.

My Foss tubes come with little gasket stickers. I use light alloy caps they match my spoke nipples.Ker bling.
I must say, 20 hours to sand down a crankset and 8 hours to sand the clear off off some brakes .
I sanded my whole Trek frame in 3 hours . That sounds painful. I can see why you took the yellow off the tyres but I would have kept the white .

Sanding my handlebars took about an hour and i haven't done the frame yet.......hoping it will be done fairly quickly like yourself.

The reason the cranks took forever was because i took them back to the raw carbon but couldn't use a blade due to some tricky angles. Will do a post on them later. I also took the carbon brake shoes back to raw carbon too with a razor. I just find those tricky angles take ages......but then i am very new to removing clear coat.......hope to get a bit quicker with more practice.

It was not a diss ,Infact Im just putting my sons litttle puch retro racer together. I sanded all the paint off
I got it down to the steel frame and it took me over 2 weeks to get the paint of. The main tubes I done in a few hours but like you are saying those awkward angles take forever . Look forward to seeing your bike .