The stock issue is your choice: return it or put-up. I'd assume Edgar Bros would replace it but you'd have to go via the dealer, of course.
How does it shoot? If accuracy is poor, check the forend is free-floating (including under load.) My CZ 527 Varmint has the laminate thumb hole stock. It shoots very well but when I first got it the barrel was not well-centred in the channel and touched under load. I found a loose fragment of bedding compound blocking the proper seating of the recoil lug. Once removed it was fine.
The moderator has failed to meet your expectations: it could be faulty or your expectations may be too high. No mod can eliminate the supersonic crack of the bullet, of course, and no one in their right mind is going to download a 17Hornet to subsonic!
The cases look normal (within the limitations of the photo). You say you are a first time reloader- the 17Hornet is a little more fiddly than bigger cases and charge-weight more critical (a 0.2gr error is a small percentage of a 46gr .308 charge but much more significant with 9.6gr of Lil Gun in the small case.)
It would be worth checking how much your resizing is bumping the shoulders back. Simply adjusting the die as per the instructions it comes with can lead to problems with headspace.
Some of my early Hornady brass had shallow primer pockets, preventing proper seating. I screened out the shallow-pocket brass by measuring depth but I'm away from my bench at the mo and can't remember the cutoff. Apparently Fiocchi primers fit but I'm not going to mess around with this.
If you use Hodgdon's online guide for min/max Lil Gun loads for 20grVmax, bear in mind that many people (myself included) found their start load over pressure despite same OAL and primer.
It's a great little calibre, I hope you get things resolved to your satisfaction.