Excellent hack so far, it's different enough from Drayanos' that it feels unique, but still similar enough that you get that feel of a high quality game. I'm up to the seventh Gym Badge in Moon Silver, with over 24 hours on the game. Part of that is due to me RNG'ing for perfect Mons, but still, I have barely put it down. The implementation of Fairy as a type is flawless, and the use of old moves appearances as Fairy moves really made the game (i.e. Synthesis' animation as Purification? Perfect!). Just a couple of things I've noticed though:
-While I understand your reasoning behind many of the changes to the type chart, I didn't have time to completely relearn the weaknesses and resistances, and so re-hacked the hacked hack (hack-ception) to have the Gen 6 type chart. While this isn't so much a con as it is a personal preference, perhaps you could have a "semi-clean" version where the type chart remains the same as Gen 6, and then a full version with your modified type chart.
-A couple of text errors (or inconsistencies) have occurred, particularly with the new moves as TM's and their descriptions, as well as some of the gift Pokemon. Things like Shadow Ball still being named as such in the Battle Frontier, Steam Shower still having Brine's description in the Goldenrod Department Store, confused me to some extent. Also, Bill talked about the Weather Institute before handing me his Eevee. Obviously this is just a carry over from the Drayano hacks, but something to just tidy up the game experience.
-Finally, be careful with changing the EXP groups of Pokemon. While I don't yet have the final Starter Evolutions, while evolving my Scyther into Scizor, the level dropped from 37 to 33, due to the change in EXP groups (I would assume). Perhaps the starters do not perform in this way due to them evolving via level, but non-the-less, just something I have noticed.
While those are a couple of negatives, Moon Silver is by far my favorite HGSS hack I have played, and second to only BB2/VW2 by Drayano in terms of favorite remastered games. Kudos to you, good sir, and I look forward to the challenges ahead as I attempt to finish the game!