Final Compatibility Build Check (Part 2)

Yes, all compatible and looks good.
Any of those PSUs are good quality with plenty of power. The "G" series is newer so get that if priced similarly, but I wouldn't be spending much more on it myself.

Couple of questions that I don't think were asked in the other thread (unless I missed them).
1) You say this is an "editing" rig, but what editing software are you using? The reason I ask is because this should guide your GPU choice. While I'm not an expert on this, my understanding is that Sony Vegas Pro uses OpenCL and tends to get more out of AMD cards (so your RX 480 would be a great choice). For Adobe Premiere Pro CC, many people recommend Nvidia hardware as it's supposedly better supported.
2) No way you can get an SSD into the budget? $80-100 gets you a decent ~$250GB SSD which will make the whole system much more responsive. Don't jeopardise your budget because it's not essential.
3) You're in a bit of a quandry if you're insisting on using that old VGA only monitor. The RX480 is digital only... so are any GTX 1060s as far as I know.
What sort of video editing are you doing? That monitor is terrible. Would you consider dropping to a Ryzen 5 1600 or 1600X and using the money saved to get a new monitor? Rendering will take ~25% longer, but it's still a competent editing CPU and at least you can look at a half-decent display while you're working. That's what I'd do in your situation with a fixed budget.

Ryzen's ccx runs at the same speed as your RAM so get 3200 RAM if possible. The 1700 is the best and the cooler has been tested to OC between 3.7~3.8Ghz. Here is the tomahawk RAM support list to help you find a good set.
https://www.msi.com/Motherboard/support/Z170A-TOMAHAWK.html#support-mem

My apologies if I was a little blunt with the word "terrible".
But your video editing which benefits from a nice large display... bigger the better really.
AND, for any vaguely professional editing workflow you want a monitor with at least relatively accurate colours

Your monitor, unfortunately, is tiny at 18.5". I have no idea what the accuracy is like, but given its VGA only, it must be old and is probably not at all accurate. What I mean by that is that the colours you see on your screen are likely to be quite a bit different from the actual colours of the video, or what someone would see if they watched your video on a better calibrated display). So when you're editing, if you're adjusting colours for natural skin tones or bright flowers, for example, you can't really see what you're doing properly.

On top of that your monitor is that it's VGA (analogue) only, which will not work with the latest video cards have all given up on.
While you can buy an "active" adapter, that actually has to convert a digital signal into an analogue one. They can absolutely affect your image quality and its very difficult to find reviews on them to know which are good or not. Given you can get a new monitor for around the $90 mark, spending 25% of that on a questionable adapter for your current screen is, IMHO, pouring useful money into what's at best a mediocre solution.

I recognise the budget issues. That's why I'm suggesting you consider dropping to a 1600X or 1600. That can save you $100. Add the $15-25 you would have spent on an adapter, and you can yourself a nice 23-24" IPS display. It's not going to be a professional editing display, but it should be close enough for someone starting out.
Here's an example of what you could get: https://www.newegg.com/Product/Product.aspx?item=N82E16824009483

In terms of CPU taxed rendering, you can expect your render times to increase by about 25% vs the 1700. But you should also consider your productivity. I do a bit of amateur editing and I'm sure I can work significantly faster on a nice large display with all my tools available vs a 18.5" one. So that's the trade off.

RE Camtasia - a bit of Googling tells me that seems to use the GPU only for the preview Window. So GPU shouldn't really make much difference.
RE After Effects - I'm really not sure here. Does anyone else know? There seems to be a widely held view that Nvidia hardware works better with Adobe software, but I'm not aware of how accurate or up to date this view is.
This is all I could find with a quick search - suggesting a GTX 1060 is plenty - but there's no comparison to AMD: https://www.pugetsystems.com/labs/articles/Adobe-After-Effects-CC-2015-3-Pascal-GPU-Performance-846/