Well, the only other minor characters I can think of is Sam's love interest Rosie Cotton and family. Without them, would the Shire have risen as fast? I don't think so. Plus, it wasn't just food and a comfy bed that kept Sam going to Mt. Doom and home again!!!
And without her, who would have taken over bag end? The foxes were a little, um, stalking? I guess they count as minor characters too. And the moth that saved Gandalf. It was a moth wasn't it? Or a bird?