Video montage workflow question.

krissserz , I am glad you understand that After Effects is not an editing app, Let me clear up a couple of things. 

Let's talk about video standards to start with. I'll start with frame size. When deciding on frame size the first thing to consider is your audience. It's that simple. You are going to be delivering on YouTube to students that have machines that differ in display resolution, aspect ratio, internet connection, and processing power. There is no way you can guarantee that you will be able to match the aspect ratio of every display so the audience will see letterboxed or pillar boxed content on some of their screens. There is no way around that unless the viewer chooses to Crop the video cutting off either the sides or the top and bottom. The world standard for HD is 1080 X 1920. It is really that simple. Even on my 5K display, HD video looks great, especially if it is well-produced and properly color graded. I've already gone over frame rates and because you are in Canada have 60HZ power and your monitor refresh rate is 60Hz, you live in NTSC land so your frame rate should be 30fps. 

Let's talk about streaming services now. All of them without exception, recompress your video and prepare different versions suitable for different bandwidth connections. Somebody on a slow connection will be served up a smaller frame size. As far as I know. only Chrome and certain Windows machines are capable of delivering 4K playback. Here are screenshots of the different frame size options on my big powerful as good as you can get iMac Pro with a 5K display:

As you can see, there are no other options. There are also no options for frame rates. Most displays will run at 60Hz, some will run at 50Hz, but there is no perceptible difference between 60fps video and 30fps video, especially with something like a screen capture of a software demonstration unless you freeze a frame. All streaming services will scale both the frame size and the frame rate based on the available bandwidth. Unless you have a specific need to create content at 60 fps, there is absolutely no reason to use a frame rate higher than 30. For YouTube content, or Vimeo, or any other streaming service, 99% of the audience is never going to get 60fps playback anyway, and your eyes can't see the difference, especially in a screen capture video demonstrating Photoshop. The only thing setting up a project at 60 fps will give you id double the file size and twice the render time. 

What does all that mean to your project? Your screen recordings are 2560 X 1440 and 60fps. That is smaller than YouTube's 4K which is 3840 X 2160 and you would have to scale down the footage to 75% to have it fit in an HD frame. Scaling up the original footage to 4K would not improve the quality of the QuickTime recording, but it would increase your render time significantly because you would have 4X the number of pixels to calculate and the file size would also go way up. 

On the other hand, if you set your project (comp or Premiere Pro sequence) to 1920 (1080 HD) you could push in on your screen capture to show closeups of things like the Layer Panel or the Brushes with very little quality loss. I've been producing screen capture instructional videos for some pretty major corporations for a little more than 20 years and I've only delivered a couple of them at 4K and those were for special events where the video was to be projected on a 60' screen in a huge arena for a big corporate event. 

I would set your comp and your sequences to 1920 X 1080, 30fps, and scale down the footage because there is absolutely nothing to gain for your intended audience by rendering 4K. 

If you want to work in and try and deliver 4K then you should invest in Screenflow because you can zoom in on the screen capture with almost no quality loss and emphasize Mouse Clicks and Keystrokes. Even if you stick with HD, Screenflow is a very good tool for this kind of work. I record with it, render Pro-Rez DI's (digital intermediates), and do my final editing in Premiere Pro using the Essential Graphics workspace and MOGRTS created and customized in AE for the titling, Info Screens, and call outs. Here's a gif showing how easy it is to zoom into a screen capture and record a mouse click that I made for this post. Took about a minute.

And by the way, HD is 1920 X 1080, not 1280 X 720. That would be HDV/HDTV, which was the broadcast standard for HD when it was first introduced but is no longer used by any broadcaster but may still be delivered by cable and satellite TV companies in places where the infrastructure is not sufficient to handle HD broadcasts or the package the customer bought is at the bottom of the list. Nobody should be working in HDV content unless they are seriously bandwidth limited. 

As I said before, I record and do some editing in Screen flow. Most of the quickie tutorials I post you YouTube for AE are done entirely in Screenflow. For my Corporate work, I always record and do the rough edit in Screenflow. I render ProRez from Screenflow. There is even an option to render Lossless with Alpha that I use most of the time. About 90% of my Screenflow renders use the standard HD preset, but some of them, the ones that I specifically know that I'm going to want to push in on, are rendered at full resolution for my screen display. On my iMac Pro that can be as high as 5120 X 2880, but then again, that is only used when I need to push in on some detail.

If I were doing what you are doing I would invest in Screenflow, record full resolution, do my rough edit in Screenflow, if there is any need to push in on some details render those sections at full resolution, but render everything else to ProRez HD (1920 X 1080), and do all my editing and final sound mix in Premiere Pro. And keep it professional, invest in a good mic, and don't add looping music tracks. 

I hope this helps. There will be folks that argue for 60 fps and 4K production but with your hardware, 4K production does not make much sense, and if you send a file to YouTube that isn't UHD - 2160 (3840 X 2160) YouTube is going to only deliver an HD copy to your audience.  

I hope this helps. Good luck with your project. 

1. Maybe. It depends on how you decide to output in question 3.

2. Yes.

3. I'd do it in Premiere. And, if you're putting it out on YouTube, I'd suggest putting it in a 16:9 sequence. Since your screen is recording that large, maybe do a 4K sequence or do a 1080 sequence and scale everything down.

That said, maybe don't use QuickTime to record things. If it doesn't give you an opportunity to record at a specific size, maybe try something like OBS that does. You can make a decision to do your screen recording at certain sizes. Then just fit the things you're presenting into that window. That way you can do it at a native YouTube size.

1. yes, if your output for the entire thing is 2560x1440. 

2. yes. if your output for the entire thing is 60 fps it would be better to match the fps all throughout your project. 

3. you can place your recording in after effects with the sequence all together and render from there. or render your sequence in after effects and place it with the recording in premiere. at the end you should render through adobe media encoder. you can change the preset to whatever res you need. make a little test with small duration until you are satisfied with the quality.