I only use 1080 for my gifs. Makes it easier for group videos so I can crop on one person. higher resolution means image quality doesn't drop when I crop.
Same. Sometimes awards show performances and the like offer 60fps versions. Pick the normal ones
Tip: If you want to use a video on Youtube for an avi, NEVER pick the the 60fps one (ex. 1080 60fps, 720 60fps) to download. It's a really large file size and makes it a mess.