In general, there are no specific laws for or against it in most jurisdictions. The main reason that casinos obtain licensing is that without it they can not obtain merchant processing/bank accounts etc. With bitcoin, you do all this yourself without third parties getting involved so in many instances, there is little motivation to obtain the license.
Even if you do not need a license, it would be worth getting one in order to give your business a degree of legitimacy and to prevent potential future issues.
In answer to your first question:Does Curacao recognise Bitcoin? It does not recognise it as a "fiat currency" however since you can use it to accept wagers, the license will cover BTC related casinos should the applicant wish to operate such.
Costs associated with the license (approximates):
1. Incorporation fees (once off) - €6500
2. Managment fees (Annual) - €4000
3. Gaming application fee (once off) - €1000
4. Annual license fee - €4500
5. Hardware costs (you need to own infrastructure) - €800 - 3500
6. E-Zone fees (E-Zone companies pay 2% tax) - €250 annual/application fee.
7. Hosting costs (€450/month)
8. Administration services €3000 + per annum
Other costs1. If you have written your own games, you will require RNG certification - expect to pay around €2500 - €3500 for this.
The costs above is more or less what we can set you up at, there are other providers who charge a premium though (licensing for instance at €12k).
Not all startups can afford the above and this is the reason we created
https://www.gamblingtec.com which allows our clients to piggyback off our infrastructure. A Gtec casino has the following costs:
1. License fee (€4000 per annum - your domain is added to our license)
2. Hosting fee (from €95 per month - depending on resources required)
3. Management fee (€450 per month)
4. Setup fee - €1000 (covers contracts etc.)
5. If you require RNG, we have a way to reduce this cost to €400 (but means using 3rd party APIs)
NOTE: Costs assume you do not require plugging into our platform which is a different ball game.