The hub limits are 5, but as this is a situation where you are expected to build a national carrier, no foreign bases are allowed. Indeed, hubs are all expected to be within one country, unless you are starting out from a small country where there is a logical reason (or real-world precedent) for crossing borders. So, I would allow some grouping in Central America or the Caribbean, in Europe the Benelux or Scandinavian countries, in the Middle East perhaps some replica of the old Gulf Air etc. Best to check with me if unsure.
The starting aircraft are 4 x B717-200HGWs, the cash is €2,000,000, and you'll get 2 gates at your chosen base airport.
As for Scandinavia, the world's second largest airline happens to be playing that front, based out of Oslo and Stockholm, but I'm sure there's room for some competition if you feel up to it :-)
Failing that, how about a Qualifyer-esque Swiss-Austrian link-up?