I’ve read a number of articles and threads on this so some of these I feel like I have answers for others I don’t.

Wanting to go around the perimeter of my house and cover the exposed foundation.
Part of the house is uninsulated slab (very cold around the edges in winter.
The other part is crawlspace: rim joists and 2″ perimeter walls have 2 layers of 1″ xps (r-10). Encapsulated, “passively” conditioned.

1. Termites. In SW Missouri (Climate 4). During part of the remodel I did find some significant damage around a door frame so want to be aware of this. In residing (vinyl) the house I installed 1″ xps over the sheathing with taped and foamed joints.  If I don’t explain this next part well, I can draw a picture. Prior to installing the foam, I took some 1/2 z bar flashing, ran a bead of caulk along the inside corner, fitted it up against the bottom edge of the sheathing and nailed it with short nails. The bottom vertical lip is tight to the foundation. Then I installed a piece of 1″ drip edge so the bottom was flush with the bottom of the sheathing and the 1″ leg was sticking out as a ledge.  Next I installed a strip of metal mesh horizontally with half hanging down past the bottom edge of the drip edge. Foam got installed with the bottom edge “sitting” on the drip edge ledge. The metal mesh got wrapped up and nailed over the bottom edge of the foam. So looking up from underneath you just see the zbar and drip edge. (Ugh, I should have just drawn a picture).
Question: with this setup, do I need to do any termite protection along the top of the foundation foam or is this enough?

2. Any concerns using the foil faced Rmax Thermasheath 3  1.5″ r-9.6? The drip edge + zbar gives me the 1.5″ room.
As an extension of the Termite question – would wrapping the top edge in foil duct tape be worthwhile?

3. Based on some other articles, I think I’ve settled in the Tuff-II protection/aesthetics option. I like the ease of the Nudo Groundbreaker but don’t know that I will like the look of that grey. The Styro site has a good faq but didn’t find anything about foil faced stuff. It says to scuff up the face of ridged foam but that doesn’t seem quite right with the foil or even the plastic that comes on the blue xps. Experience or thoughts?

4. One of the slab rooms was a garage years ago so the two exterior walls have a concrete ledge (can’t think of the name for it) 10″ high with the top covered in the partially exposed the sill plate (other part being under the 2×4 walls). Previously this ledge was tiled on the sides and top but that has been removed and will be replaced with trim board after the tile floor is installed. Even with the exterior foam, would it be beneficial to add the some 1/2, 3/4 or 1″ foam to the top (over sill plate) and sides (against the concrete) before installing the trim? Any problems, thinking moisture, by doing so? 

I don’t expect to gain much doing the crawlspace portion so it’s mainly consistency in aesthetics. And if you guys think I won’t gain anything there and it’d make more sense to just apply the Tuff-II to the foundation directly, can do that also.