Ok, but remember this is just my personal take. YM, as ever, MV.
1) All alignment protractors are a compromise, and depend on whose theories the designer follows. The Heybrook one was drawn up by PJC, and I don’t remember whose particular doctrine he was following but I’d be very surprised if there was a significant difference between the two. There’s reams of info on the net about different tracking curves and so on. You could keep yourself amused for hours, but in the end, it’s whatever sounds best when you’ve done it.
2) The original felt mat was bought in from Linn and is the same one that was supplied with contemporary LP12s. It’s not a bad compromise and I’m still happily using mine but it’s very much personal taste. People have had good results with hard rubber, acrylic and cork, and I seem to remember someone having one turned up from gunmetal which must have looked amazing.
3) I’ve never felt the need to use a weight but some people swear by them. I don’t think the bearing would be bothered much, it’s very lightly stressed. If you did end up with a dimple in the end of the spindle any competent machine shop could grind it flat and re-harden it for you. All the machining for the TT2 was done by a little two-man engineering shop near us with nothing unusual in the way of equipment.
4) Any decent quality light machine oil will do. Car engine and gearbox oils generally have a lot of additives in them to allow them to survive their intended environments. These do not improve their performance as turntable spindle lubricants.
4) Support is a tricky one, and a lot depends on your floor. The ideal is a rigid lightweight table or stand on a solid floor. If you don’t want it to wobble like a jelly and you have a suspended wooden floor, then a rigid shelf fixed to a good solid wall is best. I wouldn’t recommend standing it on or in a large piece of furniture as it will pick up all the vibrations of the panels that the armoir is made of. If you want to do that, then a substantial bit of something heavy will be needed. What I have seen done is a wall-mounted shelf through a hole in the back of the piece of furniture, but you may not want to take a saw to the back of the Chippendale.
Time flies like an arrow.
Fruit flies like a banana.