AS you say, the Wallmate would really be a lot faster. Check directly with Dow or at lumber yards, as opposed to the Big Boxes. Use as many or as few fasteners as needed to keep the XPS tight to the wall, including the bottom. I've not tried concrete nails. If you can get them to hold the washers tight, why not? Please use goggles! (I once warned a neighbour about that. He brushed me off. The next day he was sporting a massive patch on his eye after a visit to the ER.) Adhere the XPS directly to the blocked window. The idea is to keep the XPS directly on the wall; this prevents condensation and keeps the R Value as high as possible. Use XPS on the columns (actually, they're pilasters) too. If you use T&G, it's not really necessary to tape the joints as long as they're tight. The rim area is actually the most important area to insulate tightly as it's above grade. Pull out all that fg; it was just filtering the drafts anyway. And if you put plastic over it, you'll get mould and mildew. Caulk any spaces between the blocks and wood. Then fill the spaces between the joists tightly with either XPS or EPS (extruded polystyrene. Fill any gaps with handheld spray. Tape too, if necessary. It won't look pretty! But it should be tight. AS an alternative, at the rim, you could have professionals spray in cc foam. This is what I do on new homes when I'm not spraying the entire basement wall. (Some at this board say they've used the DIY sprays successfully. I have no experience with them.) Glad you persisted and got through to a Code Official who understood what you were doing!

I believe Worthy is correct. 20 years ago, it was all the rage to buy cellulose and pour it down the spaces. Of course, it quickly became saturated in all test houses and led to.....mold inside the basement. Some 2" styro on the EXTERIOR, glued on before backfilling, then coated with a latex-elastomer compound, will provide significant water-intrusion capabilities, keep damp earth AWAY from the wall, and mitigate thermal breaks. Best yet; incorporate the basement insulation (remember that 2" insulation), with the siding so that rain will run down over the siding, be directed down over the foundation insulation, down to daylight drains.

Sounds like what you are referring to is frieze board. Normally used to transition from brick to softit/fascia. The frieze board will sit in a brick pocket which helps to prevent air flow in attic and also to stop bugs from getting into the attic as well. Sounds perfectly normal.

She's planning to sell in maybe 5 or more years, so she wants to enjoy the upgrades for awhile, figures they'll help add value to her home so long as they aren't taste specific, we're removing a wall so a fair amount of work needs to be done including flooring, so while this area is ripped apart, she wants to do it. The house is not really anything in that it was originally a ranch that a living room was added off to one side and then a 2nd story was added above. So she can go in any direction but clearly nothing too formal ... no egg & dart or dentil for sure.