I can confirm Alisud have all the info you need.
From memory - weekends only, no GA movements 11-1300L plus another period in the evening.
Max parking period allowed is 3 hours.
A couple of new stands are due to be finished on the 'North' side of the airport any day now. Sounds great, but getting fuel on that side may be an issue as there isn't room for the truck to move around you on the stand.
The boss at Alisud is Marco. He's been doing the job a long time and can help you steer around the pitfalls at Naples.
If pax going to Amalfi area, look at Salerno (LIRI). V friendly and quiet airport - the exact opposite of Naples!