Are macroeconomical questions allowed here? If not, which SE site would be the best for it?
Econometric questions are welcome, for sure. If you have an "Econ 101" question, though, there is sadly no Stack Exchange for that.
I would say that Macro-economics questions can easily become very broad and hard to answer without making a lot of wild assumptions. This would then turn to pure speculation without, in my opinion, any clear answer to the member asking nor to the rest of the community. Thanks.
I think that macroeconomics can be as well considered from a quantitative perspective - moreover, pure quant researchers like Doyne Farmer are focusing their efforts into improving standard Dynamic Stochastic General Equilibrium models computationally by using Agent-Based Models; I haven't read anything about them on QFStackExchange, but these are topics definitely worth discussing.