Old Wiring Harness touch up?

A couple of more things.
#1 On several pics from dead stock harness from 67-69 a-bodies, I have noted solenoid wire (brown) running from starter relay to starter is not taped up with the rest of the wires feeding the driver´s side? What do you say?

#2 Is a 2 gauge positive cable enough to feed starter from a 135 amp hour battery mounted in the trunk.
(7 liter, 12,5 compression.)
Picture is FABO member DANA67DART´s who kindly posted it in an other tread.
solinoid wire.jpg