To my horrow I found one of the 'piston' cork like bits, was HALF MISSING

Is this a problem?
Also, most steel lines seem to go directly from the MC to the caliper, missing out the splitter. Is this a good idea?
Think the calipers are screwed to be honest, the pistons dont return easy, don't come out together, and don't come out at the same pace...
Best advice to move forward? I want my 1 finger braking back