Aluminum is an extreme vapor barrier, that would inhibit the foundation from drying, leading to saturated concrete or forcing all drying to be toward the interior, which is less than ideal. Aluminum flashing down to below the siding is fine, but below that it hurts more than it helps- there is no point to it.
Z-flashing properly lapped with the housewrap/felt to direct any water that blows by the siding outward, to drip just beyond the exterior of the finished foundation foam just below the siding is far preferable to directing it behind the foundation foam.
Only 8" of above-grade exposure on the foundation isn't huge (12-16" is better), but it's WAY better nothing.
Quickrete Foam Coating is as good as any. It rejects liquid water and doesn't wick much, but is at least semi-permeable (unspecified in the data sheets- no ASTM E96 rating) to water vapor, which is what counts.
Acrylic finishes vary in vapor permeance-
the sell sheet for Tuff-II talks about it being "water resistant" but"...not to be used in place of a traditional waterproofing", which makes me think it may be fairly permeable. Call them.