Why would you want to
Why would you want to insulate between metal wall joists and provide so much thermal bridging? Why not do what is becoming best industry practice and consider framing, sheathing and insulating different areas for different purposes? Plan ahead for installation of window/door extension jambs for “outie” installation. Sheath the outside with Huber ZipWall/tape for the air barrier; insulate on top of that with Roxul; create a rain air gap with 1x3s running vertically; install insect guards at top/bottom of air gap; install cladding of choice. If you really must install insulation between the metal wall frame then you could go with more Roxul (to better wick moisture away from the cavity).

Look for to a reply one day tanks folks…..!

On steep learning curve for our final home as we are looking into the retirement horizon on our homestead.

That would be property taxes.
That would be property taxes. 😉

True, but only if the house
True, but only if the house is kept modernized, the location has a high demand for that type of housing (when you decide to sell), newer (younger) buyers want to live in that type of house with that layout/location/lack of amenities. Too many “ifs” to guarantee that residences are truly a source of wealth. If you total all the resources (both time and money) you continue to pour into a house while living there it is, at best, a hedge against renting because everybody still has to live somewhere. But think of what better uses you could use your resources if you had a different view.

Bill – I designed a house a
Bill – I designed a house a few years back for handicap clients that needed no steps to the main floor. What I did was to install 2″ rigid foam against the concrete on the inside, then we framed a 2×4 wall 17 1/2 shorter than the basement to accommodate 18″ floor trusses and 1 1/2″ of the sill plate so we could install 1 1/8″ floor sheathing over the trusses and treated sill plate. You still have a 1 1/2″ rise from concrete to wood floor, but you could ramp it with concrete or wood. You still end up with 1 1/2″ rim joist, but it is the best solution I’ve done.
I also designed a house 2 years a go with a pier and beam conditioned crawl where the concrete wall had a reversed brick ledge to set the 18″ floor trusses in it. You need a sill plate under the trusses and a second sill plate for the bottom plate of the perimeter wall. The top of the wall was 6″ wide, so a 2×6 sill plate took must of the width and we install the floor sheathing right to 1/4″ off the edge of the concrete. Not step up anywhere, however, the trusses were 1 1/4″ short on each end to accommodate 1″ of rigid foam between the concrete and the truss ends, to avoid rot on the trusses later on.
If you have more questions, go to my website and call or email me. I hope those two ideas work for you.

If you accept Allison’s
If you accept Allison’s recommendation of 12″ walls, then I have a some ideas for you to explore. I would suggest a double-wall (2×6 & 2X4) with an ICF foundation. An interior band joist can be hung off of the exterior 2X6 wall and floor joists can be hung off of that band offset from the exterior studs. There are a lot of additional details with vapor/air barriers and window & door openings, but I could write a book here to explain it all. I do not believe in eliminating band joists for structural reasons (including convincing a code officer that you don’t need one), but there are ways to pretty effectively insulate them.