Most sally lightfoots are green/brown in the hobby, but you could've gotten a red one.It was described as "Fiji" live rock. I was looking at sally lightfoots, and your first pic could be it. I guess I'll just have to wait around!
100% definite fish eaters.
AND THEY'RE FAST AS HELL, they're a PAIN to catch. LIKE BIG PAIN. You'll need a trap.
They also I think change colors as they age.
Looks like this?