Weird build, seems low on DEX for pure SMG one. How many bursts were you able to pull off?
Why 7 INT, just for Gun Nut? +15% max dmg is not worth it, better to put it in PER for better accuracy (meaning more dmg), or pump DEX for being able to shoot another burst.
AGI 10 also seems off - just for Blitz? What do you do with those extra APs, use them for another burst? So why not just pump DEX? and leave AGI at 7.
Also, would change quick pockets for three pointer - AFAIK it gave sweet crits, especially from frag granades.
I can dig up my end game save from the run I did long before expedition came out, but I'm pretty sure I pumped DEX, and maybe PER a bit. Can't remember how many bursts I could pull and max lvl, but it beside few encounters the game was rather easy - I think I've cleared the mall without dying/reloading.
Regardless of selected feats, I decidedly find 7 INT a comfortable softcap of sorts for any character who invests heavily into crafting. In my current playthrough I started with 6 INT, but eventualy added another point just for that boost in crafting; also for the idea of not having a dumb character, but that's mostly flavor.
Like you, I would sideline Gun Nut. I've never found it worthwhile; not with snipers, nor shotguns, nor assault rifles, nor submachine guns. Haven't tried with pistols yet, but I suspect they wouldn't change my view on that feat.
Quick Pockets I find okay for the sake of quality of life, but yeah, it doesn't bring much to the table. With a bit of thinking ahead, three utility slots is almost always enough for me. If you really need four slots, I think the Utility Belt is a better choice than investing in a feat.
Three Pointer is great. Especially since Grenadier is already selected in that build, and with the 100 (134) displayed in Throwing that's 20% crit chance. And while we're in the vicinity, might as well pump Chemistry up to 112 effective skill, in order to craft Frag Grenades MK V.
Still on the subject of a grenade-intensive build, 35 points in Temporal Manipulation would net you Limited Temporal Increment. That, combined with the Grenadier feat, would allow you to throw a frag then cast Limited Temporal Increment and on the next turn you would already be able to throw a second frag.
With all that, you can easily clear a room in one turn without spending bullets, though that comes at the cost of buying quite a bit of Hexogen to craft your grenades.
If you leave INT at 7, Power Management might be nice? Admittedly more of a personal preference rather than something indispensable, but with a high-end 160+ Plasma Core you can craft obscene Shield Emitters with over 2000 capacity; and if you become literally surrounded by critters to the point where you can't move, with a shield like that you can throw grenades straight at your feet without any issue.
In other, unrelated news, I went all in with Super Steel for my current shield+machete build. Love that tight damage range on the machete.
Presently I'm some minutes into the expedition, and oh boy I'd forgotten how tanky some enemies are. The good news is that my character is even more tanky and with good damage to boot, but the mechanical resistances are something and a half. I still have a 178-quality Super Steel plate waiting to be paired with a good Energy Edge Emitter to—hopefully—alleviate the problem somewhat, but so far no luck.