Too Fat Lardies

The coats are pretty different between F&IW and AWI.
Short coatees for the later, longer coats for the former.

The strategic level of Blucher (which is called Scharnhorst) uses stylised squared maps (one each for Peninsula, Central Europe, etc) One these one moves columns which are generally corps-sized formations - when they get close someone can declare a battle which is an area of 3x2 squares on the map. ...

Marksmen, like every other unit, only get 2 actions per turn (except for the things like Sharp Practice) Initiatives can be used more than once per turn (e.g for rallying) but each unit can only be activated once. Also, a skirmish formation doesn't fire volleys, controlled or uncontrolled. It uses s...

There have been several scenarios posted here

No - the fur is synthetic. You won't be able to dye it.
Spray paint is probably the best thing

The templates work fine for turns, but how do you handle the more complex things like side slips, jinking, split-S, barrel roll, and so on?

If you used two Blucher cards to represent each unit it would work.
Put the cards side by side for line, one behind the other for attack column, and end on for road column.
Shako scenarios should work fine for General d'Armee

The Italeri 1:72 plastic buildings work very well with 28mm (and they have lift off roofs, too)
But I also use them for 20mm.

My advice would be to stick with 15mm buildings.
It's much better to have building a bit under scale, so they take up less space.
Overscale buildings don't look good.

I use pink and blue ovals of card with letters (A..L) on them. These work with all nationalities (and eras), and they can sit on terrain. Anything with modelling on it won't sit nicely on bits of terrain. Not sure how others remember which blind represents what - I find the letters very useful - jus...