Community: Energy efficiency and durability

I'm looking for advice (and a little comfort) for the following situation:
We are in the process of building our own home... slowly.

Our exterior wall as designed is as follows:

Wood clapboards
1x strapping
felt paper
2" foil faced polyisocyanurate insulation (taped joints)
1/2" plywood sheathing (taped joints) (dedicated air barrier)
2x6 stud walls with Roxul batts
1/2" gyp bd, painted

We have all of the ductwork in place for an HRV, but it is not yet installed.

The interior of my cobblestone foundation needs to be repointed. No stones are loose, but there are deep pockets in a lot of areas.

As part of a complete gut and remodel taking place this spring, several professionals have suggested that instead of repointing with mortar, that I could simply have the insulators spray the stone with foam as they are insulating the walls and ceiling.

Built the dream log home and now face the heating nightmare in Climate Zone 7. A masonry heater reduces the heating load of my in-floor heating system by half but without it my heating bills avg $500/mo. Here is my wild idea to reduce heat loss:

1/2" or 1" rigid foam against interior of perimeter log walls
Log siding nailed against rigid foam

Has anyone ever seen an analysis that indicates the benefit of having an air source heatpump run more before the nightly temperature drop in order to obtain a higher COP than later in the night?

A similar pre-charge could be done for cooling before the outside temp rose a lot.

In the past with leaky poorly insulated houses I don't think this made much sense, but now with some very tight and well insulated houses I belive it would be beneficial.

The main trick is to mine weather report data and control the thermostat based on COP curve, energy loss rate, and heat schedule.