I'll leave most of the answers to the pilots on this forum, but I can answer two small details.
During landing, Concorde isn't flared at all, it is flown onto the ground at a constant pitch attitude.
What does happen is that the ground effect over the last 50 ft or so of height considerably flattens the trajectory, so you do not touch down with the same vertical speed as during the final approach !
What also happens is that the ground effect produces a pitch-up moment, so the pilot has to push forward on the stick to maintain the same pitch attitude.
Putting the nosewheel down after touchdown is enough to completely “ruin” the lift, so that there is no need for “lift-dumpers” or spoilers.
CJ