You are worrying over nothing. You could probably remove even more metal from the top strap and still have it be perfectly safe. It's a darn good looking gun and I bet the 3.5" barrel balances almost perfectly. I have a 4.2" blued GP100 and find it "just a tad" nose heavy. I feel is due to the full underlug. (One day, I may send it off to get slabsided or have the underlug cut.) It's not really a big deal thought and still feels better than most other .357 service wheelies.
Also, I give them kudos for using the old-style (Lett) factory rubber grips. I wonder if Hogue, TALO, or Ruger bought/copied the mold design? I know they aren't surplus rubber with new wood because they have the "WC" logo on the backstrap. (Lett out of business a few years ago, hence the switch to the standard Hogue Monogrip.) Regardless, I think most people will prefer it. The only way they could have done better is to have used the "compact grip" that came on the 3" and fixed sight models. (These were the ones that used SP101 insert panels.) I have a pair on my GP100 and think they are great.
Sic Semper Tyrannis