the rear connector looks to be a juction for hard brake line to rubber flex line
normally at a point where the body of car moves(like you thought)the others
could be a union connector but not sure(reuse as mentioned). the parts house should carry muliple sizes of lengths from 6'' - 6 ft.as far as flaring lines yourself im not into the extra time/tools needed.you prabally have about 20-$25 of parts + brake fluid.just measure the lines with tape measure they will be able to get real close
Good luck mike