Hello Ana,

You can apply for the Non Lucrative residence permit even if you have a schengen visa for 5 years. Note that in order to keep your residence status once you obtain the permit, you need to spend at least 6 months per year in Spain. The NL residence permit will indicate you are a spanish resident and therefore you can travel within the Schengen area and stay there for 90 days within a period of 180.
When applying for the permit, you will need to prove you have sufficient sources of income. If you are dependent on your husband, you will have to prove regular transfers into your account (spanish or foreign account). You can certainly use your parents´ in law´s address for your residence permit application.

Regards,