One question we have is can too many needles and leaves prevent flowers from growing?

If so, are there any particular flowers that may grow well in this kind of environment?

Also, are there any tips on how to keep up with removing all the pine needles and leaves all year long from such a large area?

You can check with garden clubs or with the county agricultural extension office in your county to see what plants thrive in your area.

The ones I can think of that grow in acid soil in shady conditions are azaleas & camillias.

If you post an ad on craigslist or freecycle, "free pine needles, rake your own", I bet you'll get a lot of fresponses from eager gardeners!