As already posted any resort guest can do the campfire sing-a-long, hayrides and EWP.
The logistics depend on how you get to FW. If arriving by boat, the zoo is just past Pioneer Hall (a short walk from the dock), the hayride starts in front of Pioneer Hall. If driving to FW you will park at the entrance and ride the bus from the Outpost to Pioneer Hall. (The orange bus line runs down the center of FW.)
The pony rides at the petting zoo end at 5:00 pm and the zoo remains unlocked until sunset I believe. (have quarters ready for the food dispensers)
The Campfire is located behind the Meadow Trading Post. you can get there by walking (about 1/2 mile or so) or by bus. The sing a long begins at 8:00 pm (summertime) and the movie follows at 8:40 pm. They have a chuckwagon that sells fixin's for s'mores, sticks to roast with, popcorn, drinks, etc. (you can use room charge)
The EWP is at 9:45 as previously stated and is located on the waterfront down at the docks.
I was just there Wednesday - did all the things you wanted to to except hayride with no problem. Had plenty of time to shop in the trading posts, play a spirited game of tether ball, enjoy the peacocks roaming around and eat a great meal at Trail's End Buffeteria.
Hope this helps!
IMHO this is a great way to spend an evening at WDW!!
Have a great time!