Even though I have DisplayCount set to 35 for a Dropdown Combo Box List, only 30 choices are displaying on a particular Form. Does VFP have a limit of 30 for a Dropdown List DisplayCount? Or does VFP limit the number of items displayed based on Form Size?

Yes, Form Size can be a limiting factor. Adjust your Item Height and Font Size to see if your total item count changes. And you might try to drop your DisplayCount to 10 or 20 to see if more items are visible when scrolling.