Just to confuse this issue further.. At one of my previous locations, the region has amongst the lowest mean income levels in the country. Not everyone has wealth to spare for an Internet connection. This school decided that the better option was to use Moodle as both a source of content and a provider of as many varied activities in all subject areas as they could. Teachers would generate their own, agreed, content, usually from their existing resources, mostly electronic, and each teacher would use their own activities based on the agreed materials.
In some subjects this was a difficult choice, as many teachers were unfamiliar with using the Moodle and were stuck in the pdf resource, word worksheet model endlessly repeating itself. Some were providing lots of content, but not a single activity on the Moodle. Last I talked to someone from that school, it was getting better, but it is taking time.
Essentially, you can use, or not use, Moodle features as you see your need developing. Sometimes you need to experiment with different ideas. One thought is to use Hot Potatoes to generate quizzes, rather than Moodle's internal quiz maker, My suggestion is to construct modules that allow an easy integration with other popular PHP applications, rather than try to reinvent the wheel, (that is a Moodle issue though, not a User one). As long as Moodle can provide tools and opportunities to create activies used in conjunction with accessible resources, it does not really matter. What does matter is you use Moodle however you feel comfortable with, and then as you get more confident, expand what you can do with it, but always remember, the Clients, the students, are the arbiters of what works and what does not, so always listen to them.