Re: Gopro film settings
If you want smooth video flow then shoot in 30fps or 60fps and post process in a 30fps timeline. The 60fps will give you the ability to slow down the footage 50% and have smooth slow motion. A 24fps shoot will match up well with other 24fps footage that is shot on say a DSLR for the "cinematic look". Whether it is the look that you want in your final production is up to you. Personally, I'm not a fan of GoPro footage in a 24fps wrapper. The camera is geared towards "action" footage and the 30fps timelines in post fit action footage better in terms of smooth feel and a more realistic look. The sensor in the GoPro just does not allow the 24fps footage to match up visually IMO with DSLR footage without a ton of manipulation in post.
As far as 1080 vs 720 vs 2k vs 4k ... In reality for most people this will matter little. Where 2k and especially 4k will shine is for the person wanting to use a frame grab at a still photo. Or the person wanting to zoom in very tight in post.
I shoot video professionally and shoot most everything in 1080. However I do the bulk of my post production in 720 by scaling down my 1080 footage. This is generally fine for anything youtube and even broadcast material. The bulk of my clients want something on a DVD that they can pop in their DVD player, so the footage gets scaled back to SD anyway. In the case of BluRay, 720 is more than sufficient as it matches with the bulk of broadcast HD here in the States. There is no reason for me to produce video in 4k. So few people have 4k TV's (I don't even own one) or monitors. It is overkill at this point in time and eats up tons of hard drive space.
I've found flying my GoPro's on a H3-3D gimbal at 1080 60fps, ProTune, Automatic WB, 400 ISO, and either a ND4 or ND8 (depending on lighting) works excellent. It produces great footage that is very smooth in post with just the right amount of motion blur from the slower shutter speed thanks to the ND filter. Now if I want quality still photos then I send it up without the ND filter because I want a fast shutter speed for the crisp details. With the ND filter you will get soft edges on your photo subjects.