As Onderzeeboot said, drafting your cube is the most valuable feedback you can get. You can theory craft to a certain degree, but a lot of your assumptions or worries will be stripped away once you actually start playing.
One of the great things about a sacrifice theme is that you can build it with cards that are generally independently appealing. This is a good quality, because it provides a few things:
a) you can draft cards from this theme without fully committing to it
b) you can use sacrifice effects as a subtheme in another deck
c) most importantly, since there is competing demand for cards in the sacrifice theme, your decks will look different every time. It's not just the storm drafter collecting the storm cards, but everyone will be cutting into these cards to some degree
These cards will get put in decks because they're good cards. But, on top of that they have lots of nifty interactions. Then, if you have a lot of sacrifice effects, you can take one of a few "dedicated support" cards like Goblin Bombardment.
The sacrifice theme is a nice one because your players can audible to an aggro or midrange deck, but a dedicated sacrifice deck is quite a joy on its own to play.
I guess you described sth similar to this in your article about life gain in cube: we run cards which are independently nice and fit well into other decks, but which can also form their own theme/subtheme, if we want them to. I thought I understood this thing, but I've just realized that I haven't been fully using this approach in designing archetypes. Fortunately, I still have time to do it Thank you!