I can see why they keep telling you "no". Those are not trivial things and they would require changes to the Canvas core. That is, they aren't simply adding on features, it's a major rewrite of the way that things are done. Those kinds of projects (like quizzes, speedgrader, gradebook, and communications) take a long time and a lot of resources to rework. It isn't worth it to Canvas to dedicate that kind of engineering resources and pull them away from the other projects that are going on. They want to focus on their core product, not writing custom code or external apps for people that they then have to support. The best chance you have is to get an outside firm or programmer to write them for you.
Attendance has been a hot issue for years with the last date of attendance requirement. The Attendance Overhaul feature request, currently on product radar, was created by our Canvas Admin back in April 2015. For our online courses, we measure student participation in the course -- participation as measured by submitting something, not just logging in.
When you say uploading photos to an assignment, do you mean in addition to the assignment itself or as the sole submission to the assignment? One could upload a photo to an assignment, but the back-end support is not there for processing multiple attachments to an assignment. One approach might be to have the students submit the photo first and the document second. It might be able to be handled the other way around, but Canvas defaults to showing the last submission when there are multiple ones. Then, on the screens where you need the photo shown as well as the assignment, you could put in some custom JavaScript that would fetch the additional image and add it to the assignment.
The two-assignments, two-photos thing is way outside the realm of anything that Canvas can do with its core functionality. It's not setup to handle multiple attachments as part of the same submission, let alone displaying two student's assignments side by side. There's nothing that I'm aware of that would keep someone from writing code that would load the additional assignment and photo when a page is loaded (it might get crowded on the screen), but through API calls it could probably be done. You would have to modify the existing behavior on the page, though, as you're not going to be able to add an extra route without access to the source code.
If you were self-hosting, you could make the changes and make them part of your Canvas, but if you have a hosted solution, then you would need to accomplish all of this through custom JavaScript.
I would not incorporate these into Canvas, though. Instead I would write an external app (LTI tool) that does photo / assignment / resize / dual display thing. Building it into Canvas through the custom JavaScript means that someone has to watch out for breaking changes every three weeks when a new beta release is made. I have written a lot of add-ons that individuals add to their browser to change the UI to work smoother for them. It's a long process and involves a lot of research into how Canvas generates things. Then, since it's all undocumented, it could change at any time without notice. When I visited with Instructure product managers in April, one of them suggested that I would do better to focus on external apps like the Google Sheets or an LTI rather than trying to make custom changes to the UI itself. I've got to agree with him in this case. Making it an external application means that you can communicate with Canvas through established and documented means that are rarely going to change.
No one is going to be able to throw this together at Hack Night; it's definitely more than a couple of hours of programming. I doubt any of the engineers from Instructure will touch it because they realize it's going to be really difficult to do with the current core and they know how hard it would be to get approval for the changes needed to do it. There is mention of Atomic Jolt and Cidi labs being co-sponsors and there may be other people willing to do programming, so hopefully you will be able to find someone who will take it on. Both of those companies are Canvas Partners, so you might reach out to them ahead of time instead of waiting for InstructureCon and Hack Night. That link shows other partners and allows you to filter by category to help find the right partner for what you need.