I use the kit (clear) shocks. As I said, it's a waste of money to buy the TRF.
Yes, I used the internal spacers and I think there was no need for external (I will check again when I am home).
You don't need travel. On the contrary, you want the car to be as stiff as possible (within reason) without getting into traction roll.
The main problem with the rear motor minis however will always be oversteer and that is only addressed by your driving.
I did not weigh it too carefully but I think it's close to my TC sedan which is about 1425g.
I will play with it some mor ein the coming week on my break, but don't have too many new ideas. I will just play with tires/inserts.
My main obsession is to get rid of as much slop as possible. I know this is not essential in a mini, but that's what I need to be comfortable. On the upshot, my car is going straight as an arrow and that's what I like to see before I start tweaking this and that. Otherwise, I feel like trying to drive a greasy weasel.