Please forgive my total lack of understanding of DNN but I am trying to learn and asking questions here hopefully will lead to my enlightenment.
I have been doing simple pretty much static content sights in Frontpage and Expression web for a number of years as a sideline to my tech consulting business and I am tired of doing monthly update work for customers so I am searching for something like DNN or Joomla to allow me to manage the sites and assign permissions but the customer can manage the content. I am going to build a test host site using a a skin / container package I found and I am wondering about modules before I purchase a skin package.
before making the assumption that modules are interchangeable between skins / containers I thought I should ask the knowledgable hoards.
If I buy a skin / container package can I assume modules I find to do tasks like stores with Paypal support, Picture displays and email communication can be intigrated into my DNN installation using the newly found module?
Are there underlying basics about how or in what coding language was used creating skins or containers that will govern what modules I can use?
Can I add containers to a set of purchased skins / containers without rewriting code by hand?

Sorry for my total lack of understanding but I am trying to learn.