There is no harm in adding all of the addresses to the website, although i would certainly redirect via 301 to the master, dominant (or preferred) domain.
One of the main things you need to be careful of with multiple domains is duplicate content, Google will view the website for www.goldenstategolfandputt.com and www.goldenstategolfandputt.net as two different websites even if they are the same website but just reached via a different domain. Therefore if not addressed you would get penalised for duplicate content, to overcome this problem do either a 301 redirect or a rel=canonical to resolve this.
Also unless there is a very good reason, i would ensure from a simplicity's point of view that all linking, internal and external points to a single chosen domain as managing inbound links to multiple domains can be a real pain.
In essence, there is no problem with using multiple domains, plenty of people do it to protect their brand, to overcome misspellings, passing off etc etc.
Hope that helps
