I have three Trimma canas, along with a pair of Elacatinus oceanops, and one Coryphopterus personatus (had two but one was beating up the other). I'm going to add 3-4 Eviota pellucida very soon, and a couple more T. canas.
T. cana is a bottom dwelling percher for the most part, sitting motionless on the sandbed until a piece of food drifts by. Then they leap up to grab the food, and back down quick as a flash. They don't swim around at all, so be prepared for that. They also don't school, in fact the opposite, they spread out as much as the tank allows. One of mine has claimed a hole in a flat rock, and has a girlfriend who comes by every few days for some bow chicka bow wow then goes away again (sweet deal). Even for their size T. cana is a light eater. I can't give you a definite answer on longevity, but I can tell you it's not too bad. There IS one Trimma goby that only has about a six-week lifespan, but it's not T. cana.
Elacatinus oceanops I'm sure you're familiar with, very similar to your E. evelynae but prettier IMHO.

I love them. Voracious eaters for their size; active, fearless, peaceful. I'm also tempted by the rarer E. figaro (yellow stripe version, only ORA has them AFAIK) but I'm concerned about them getting along with my E. oceanops since they're so similar.