Stone brick and block rendering

[frankquietly]

Hello, have chipped off all the old cement render to discover some flint stone wall, soft red brick and breeze block (the very soft type), photos below. Quite the mix. I'm thinking of building back up with lime mortar in the gaps, lime parge coat, breathable insulation like wood fibre or cork, lime plaster. Does that sound ok considering the different walls? Any suggestion for a better approach? Gotchas?