here is my quick review after getting to Tier6-7 content in a FU playthrough, wall of text incoming.

Neki is like playing FU on hardmode.

The movement speed bonus while very nice early game doesn't really cancel out the moderate damage & absolutely massive durability penalties. this works fine for early game stuff like overworld exploration or early game dungeons where you can dodge everything or parry/block the things you can't. late game dungeons like the FU version of the ruin fight, the precursor mission, and delta freya are just getting 1 or two hit killed by anything that deals physical damage unless you dedicate your armor and EPP to pure tank stats. I have never had a more difficult ruin fight than with this mod.

While very thematically appropriate the weapon buffs are pretty weak IMO, fist weapons kinda suck against anything you can't stunlock (not to mention have way less variety than more standard weapon types) though the actual racial neki claws are pretty decent until you can find a force gauntlet.

You asked elsewhere what weapon mastery did? it's actually varies between weapon types, for sniper rifles it's a small crit chance boost and a ammo capacity boost (if you use a rifle with the FU ammo system instead of just energy costs). 10% sniper mastery is pretty small, considering the neki's built in damage penalty and half of the bonus is basically wasted where you're conflicted between using a pure energy based rifle to leverage nekis massive energy pool or a ammo based rifle to take advantage of mastery. As a personal preference i do prefer races with 3 different weapon bonuses (or more generic bonuses that apply to a variety of weapon types) to add more variety to a playthrough.

And probably the most unexpected weakness of the neki is the diet restrictions, in Starbound cooking Milk is used in everything at least almost all of the high-tier non-robot buffing foods require dairy and the that don't require fruit. and yes I'm aware you don't intend to change this.

Alright now onto the positives, thematically it's very strong with things like the fist weapon / sniper mastery (was that an intentional nod to IRL cats having poor close range vision but good long range vision?) and the dairy/fruit allergy is also appropriate despite the gameplay problems i elaborated on above. going fairly fast and jumping high at the start of the game is very fun at least before techs make it obsolete.