Ken,
I think the concerns about using steel shot are well founded. In SD, they require non-tox on public land for upland (phez,grouse,huns, etc.) hunting now. I'm sure the situation on use of lead is going to get more restrictive rather than less, in the future. I think non-tox requirements are on the horizon all over the place.

If a guy gets $10-15k invested in a gun, he should be assured of it's viability as a hunting gun for decades. No sense creating a gun that might have very limited or no utility value, shortly down the road. I think some of these guys would like to be able to pass along a hunting gun that their offspring could use.

So, your suggestion of hardchrome (or possibly Ti-Nitride, like the RBL) plated bores is sensible to me.

Mono-blocked barrels would be ok by me, IF they don't rollmark the joint like many inexpensive guns. You may also consider looking into having the barrels either Electron Beam or Laser welded into the monoblock and then the weld normalized and blended. The filler metal would likely have to be a raised lip on the monoblock or the barrel, or could be a third piece that is added. I'm no weld expert, so you should seek someone more versed in this area. But, I might prefer a EB or laser welded mono-block to a soldered one for this gun. BTW, I did a sleeving job where I TIG welded the barrels to the "mono-block".