Honestly, those stats are excessive. First, you gave him a Marine's S & T. That's a no-no for non Marine characters - you can't get there via training or experience, only through implantation. Look at the special characters in the IG codex - without exception, they all have a base of S3/T3. Gaunt is the only one who exceeds that, and that's through using a powerful weapon that grants him +1S in a fight. On top of that, you're giving him +2S in a fight...
Second, the NFW. That is a holy weapon of the Grey Knight order - and no, just because he's an Inquisitor Lord doesn't mean he can requisition one. The GK wouldn't allow a non-GK to use a NFW, same as they wouldn't let a non-GK wear GK heraldry.
I like the Crown, I like the no other HQ rule, and I like the no retinue rule. But I really can't agree with the stat choices you've given him.
I understand that you want more than S3, as that's pretty terrible in combat. You could give him some kind of tweaked Daemonhammer, perhaps, or make up a special weapon. I think a Daemonfist would be kinda cool
As a result, you could probably drop the points down a bit.