All Aruba hotels restaurants are open to non-guests, you won’t have a problem eating and establishing meetings in them.
Some Aruba hotels are more expensive then others. The best course of action is to shop around and compare prices and packages that are available during the timeframe you will be on vacation. If you go in the off season and not the busy season you can save a lot of money.
Many people pay for their traveling by working in jobs that are easy to obtain in the places where the visit. Aruba hotels might be one such place. If it is possible you son can take advantage of some great amenities and pay for it all while he is there.
There are a lot of great places to send couples on their honeymoon. I would suggest going online to some of the travel websites and they can give you a pretty good idea of what is available and the specials they may have for newlyweds. It is wise to shop around and try to take advantage of the package deals available.