That support member, "H-member", around the jack tube is a structural piece tying the jack tube to the outer rocker (at the top and bottom) and depending on location front a-pillar or other structural member. The fact that it has shifted down and out is not good, can you move or wiggle it, is it still attached inside the rocker?

As far as the brakes, what did you do? Mushy brakes are usually a sign of air in the brake fluid or boiled fluid, did you bleed the brakes?