using red for the panel lines on unicorn would be good, since the psychoframe is red, therefore it would enhance the look of it
you can use the thicker markers and use paint remover (not thinner as i think that would damage the figure) and clean it up, or get the red gundam markers for about RM10-12 each and panel line it using that.. hope that helped

yeap, personally i think unicorn is well designed enough to not need panel lines but that's just my own personal taste.. hehe
the unicorn mode may need panel lining though.. as destroy mode already has red to break up the pieces

Make sure you've trimmed the leftover nubs from the psychoframe parts E14-15. There are two nubs at the distal end of the pieces (near where PC6 goes) which could obstruct C7 as you slide the former into the latter.

Also check the polycap piece PC9 as it might displaced if you couldn't clip E14-15 together tightly.

And since we're on the topic of the Unicorn's forearm, be cautious of the beam tonfa holder. It's held loosely in place between C2 and the tip of C7 solely by friction, and a little nudge is enough to dislodge it especially when it's extended forwards. You might accidentally flick it off if you're not paying attention.

Real Touch Orange