Hmmm.
Str 5 is fine the best early - late mid game shotgun is the caravan one, take rapid reload and a high agility it's perfect.
Per 5, since you plan on getting close knowing where even is would help, but take ED-E.
End, 7 is a joke ?
Cha, why take this so low then tag speech? blooming heck power G, Basic ammo will now cost 2 caps from the start, and slugs 4.
Early on if you truely plan on a "shotgun" build will make it a tad harsher.
Int 6, 5 is enough for most builds skill points are only rare under 3 and or with multipule weapon skills.
A 8, this is perfect for shotguns in fact is the right choice 100% imo, if you take small frame it gets better.
Luck 8, Not needed on normal with guns 60ish and a slug loaded caravan you can kill giant rads in roughly 6 - 10 seconds.
Even quicker with rapid reload and shotgun surgeon.
Look for a great build that can do anything and is focused in shotguns, just set everything at 5, then bump agility to 8 and place the last two anywhere you like.
This has no weaknesses and tons of strength, it also does not you requiring mass hikes to stats that everyone thinks are powerfull, and dump those that are not in peoples minds.