Framerates:

for capturing high speed action, being able to pull stills, and to convert to slow motion, the higher the frame rate the better. For example, 30 fps is what most online video is shown at (technically 29.97). So something filmed at 60fps can be slowed to 30 fps to give a half speed slow motion with normal quality playback. 120 fps would give you the ability to .25x, etc. because you are capturing 4x as many frames.

If you want that cinematic feel, shoot at 24 fps. You can't adjust this to slow it down, etc. but it will give the feel that a typical film has as this is the rate the MOST films are shot at (that has changed with a of big action films recently, shooting at higher frame rates). So if were wanting to create highlight video with no slo-mo, etc. and shoot it a wide format, it can help give you that feel.

4K is going to take up a lot more space, and you won't have as many high frame rate options as 2.x or 1080p - but you can also crop and zoom in, etc. and still maintain good quality.