ConsolePort 

I will look into that. Anyway, you can already bind the mouse toggling function. It's under ConsolePort in the list in the binding manager. Though, you can't disable the automatic toggling atm.

I'll probably just add an option to disable it.

Seems like I have to get my hands on one. It's hard to develop for it blindly without actually trying the features it has to offer.

Anyway, what kind of setup are you using right now? Are you using RT as shift and LT as ctrl and if so, did you find that comfortable? From what I've seen in videos, it seems the shoulder buttons are really clicky, which might not be the best when used as modifiers, which is why I chose the triggers as modifiers for the Steam controller.

The bag addon was a part of ConsolePort, because I was dabbling in creating a separate interface for controllers. Decided to scrap it because it was not that good compared to other bag addons and I felt like developing ConsolePort to work with any interface instead.

Good to know. There's a workaround for Xbox controllers, but since the DS4 is the only controller that does it without issues, this makes me think I should move over to a modular system where each controller has its own setup in place, instead of a general one size fits all approach. This would also create an environment where you can utilize the grips on the Steam controller as in-game bindings.

The permanent right click to get your camera moving is not really necessary. The addon does this for you already and it responds to in-game events unlike a statically bound right click in the Steam config. I intend to add more customization to that system soon, but right now, this functionality is essentially already covered. You can customize mouse events and it triggers automatically when you move your cursor on top of your character and triggers off when you right click.

The virtual cursor from the addon is my solution to get rid of the extremely annoying and unprecise UI interaction of a normal game controller. You can imagine how annoying it is to click the interface with a thumb stick, considering the interface is tailored for mouse and keyboard. Do you think the virtual cursor is unnecessary with the Steam controller?

I'd say the Steam controller isn't even officially implemented yet, since there's no profile and I haven't tested it yet. The icons are pretty much just copy paste from the Xbox layout, except I changed the Xbox icon to a Steam icon. I'll fix that.

/framestack is used to get the name of frames you want to add and you don't put it in the popup, you type it in the chat, similar to how you would type /dance.
Anyway, if you don't know what you're doing, just reset the settings and you should be fine.
This is how to do it:

Did you accidentally remove "Blizzard_Collections" from the interface settings?

Thank you, and yes, I do need a solid Steam controller profile since I can't seem to create my own without actually owning the controller!

I'm going to go ahead and paste the instructions from the main description about the do's and don'ts when it comes to creating your own profile for use with the addon.
If you have any questions about the process, ask away.

Instructions have been modified for the Steam controller!

The layout is a bit different for Steam controllers because of what I've heard from reviews. Whereas the Xbox and Playstation setups use L1 & L2 / LB & LT for shift and ctrl, the Steam controller icon layout uses RT as shift and LT as ctrl. I would like feedback on whether this is a good setup or not, since I personally don't have a Steam controller and can't test it out. If you think using only the left hand side for modifiers is better, I'll revert the change in the next patch.

Well, this is exactly what the addon should be doing for you. I know the Steam controller has paddles too, but on a normal Xbox or DualShock controller, you have 52 bindings at hand without swapping action pages because L1 and L2 are used as Shift and Ctrl. The fact that you mention Shift/Alt at all leads me to believe that you're not even using modifiers in your setup.

I find this really hard to believe. Keep in mind that you can't combine arbitrary buttons such as A+D or F1+F2, but this addon is built upon converting normal keyboard input into several different outputs by using Shift and Ctrl modifiers. If your controller is converting to keyboard input correctly, WoW should pick it up too.

A correct setup works with the cursor without fault. Again, it sounds like the profile you have set up isn't actually tailored for the addon, but rather just tailored for WoW in general. I'd like to stress that ConsolePort does not handle key bindings the same way that WoW does it natively. You should in fact not even have to touch the normal key bindings at all. ConsolePort generates fake bindings for you, granted your controller buttons are correctly registered.

So let's sum up:
1. Keyboard keeps popping up for unknown reason if not disabled.
2. You find the binding setup too limited for DKs.
3. You can't use modifiers to access different abilities.
4. You can't use the addon binding manager.
4. The virtual cursor doesn't work.

My only conclusion is that your setup is flawed or incorrect in a lot of ways. The automatic mouse look is just one of many features the addon has to offer. If you can, please provide a detailed breakdown of your setup, along with screenshots both in the Steam configuration and in-game. There are instructions to creating custom profiles in the addon description. Did you follow those instructions at all?