1. A Troll surged early in his life and got Neoteny. How tall do you expect him to be and does he loose the increased movement speed and arm reach?
2. A Human surges getting Metahuman Trait (Gigantism). Does he get Troll movement speed and +1 Reach?

What do you think?

1: Yes, and looks like a child Troll for the rest of his life. Which is still pretty fraggin' big!

2: Sure, why not?

Whatever the rules say, which I assume is 'no' and 'no'. Serves you right for using SURGE, heh.

Wouldn't it be easier and more cost effective to do it the other way around, and make a troll with Lucky?

Just fluff it as getting a healthy dose of the human luck gene, You might be able to let your GM take Lucky as a Metagenetic Quality through surge.