EOF is not allowing me to place or move half notes. I'm only allowed to place 16th notes, I'm not sure why it's doing this. Can someone please help me?

Change the grid settings under the Edit menu.

You can also use , and . to cycle through the preset grid snap sizes. The Information panel will display what size is currently in effect. Alternatively, you can use a higher grid snap than you need, and just increase the note length (ie. placing a 1/16 note and using ] or scroll wheel up will increase it to a 1/8 length).