happy to look into this with you, this is likely something very simple, feel free to email me deva@opstarts.com. also, there is going to be a "modeling freemium" knowledge base article posted today.
yes, def good suggestion. the templates are right now only sorta useful since they arent really documented. i'm working on that and should have basic stuff done this weekend, that'll make them a lot better and we can think about adding more then.
A feature that seems missing (particularly for bootstrapped startups, but useful for others too) is using a % of profits or revenue to fund user acquisition, rather than a $x amount that grows by either Y% or $Y.
OTOH, that would assume that channels don't get saturated, so you'd also need a ceiling on the max spend for that channel.