The build is fine as it is for normal but if you want to improvements i do have some opinions on that.
Changes i would make:
ST 5 to wield your guns, ST 6-7 give you only small benefits which are an st 6 shotgun type and a unique sniper while st 7 gives you full auto feat. all of which are either replaceable or just not worth the point investment for a sniper/shotgun build
Dex: 5 for leading shot, 6 if you want grenadier feat.
Agi: 3 is fine, 6 if you want more maneuverability by taking sprint feat which lets helps you move to cover easily after taking a sniper shot from stealth. the value of this drops over the course of the run as you gain more and more mobility gain options but early-mid game its great and is still useful in lategame.
con: 3 is totally fine, you could go 9 for survival instinct but that considering its your first run lets keep it simple and just stay at 3
Per: 10 at all times as its your main accuracy and dmg source. feel free to invest further 1-2 points to other stats like int as 18 is likely overkill for sniper/shotgun as you already wield the hardest hitting guns
Will: you are only using PSI for utility, 3 is completely fine for this role while investing any more would just be a waste.
Int: 6 is recommended for premeditate and crafting stats as crafting is a valuable thing in this game and going low on int as such is not recommended. going higher than 6 is fine as that only makes it easier to increase your crafting stats to what you want.
For feats i would drop suppressive fire and kneecap shot as the former is fairly weak for shotguns and same can be said for kneecap shot as PSI is likely the better alternative requiring only a small investment in stat points and no feat slot. i recommend that you dip into metathermics and/or psychokinesis for more CC options. the increased PSI cost won't be too much of an issue when only used as utility and premeditation should help with keeping the issue in check
Perfect scattering is generally considered a weak feat as the damage boost is minimal and is usually avoided for better options
Barrel stare somewhat conflicts with leading shot as barrel stare does not work at leading shot range while leading shot does not work at barrel stare range. you usually want leading shot benefits over barrel stare so you can consider dropping barrel stare if you need more feat slots.
Feats i would recommend that i have not already mentioned above are the + crit chance ones and snipe as its just really solid high damage alpha strike even with average stealth investment
For spec points i would drop 1 point from crit power and move it to shooting spree as it essentially doubles the value of the feat for just 1 point. Generally worth the small loss of damage from crit power.
