Hi Charlie, it sounds like you've done a great job! You've identified the main issues, received input directly from users of the request management system, digested it into manageable chunks and then addressed things according to priority. I like that you're not getting to bogged down in detail in the early stages too, which is something I need to watch myself on.
Next: It's worth getting feedback on the prototype once it's at a point where the users will be able to see how to use it, and setting up an iterative process from there (to test and balance design changes as the prototype or final system matures).
There are probably some priorities you discussed during your 5th point (the UX team session) that it may be useful to articulate and record. These will be helpful when presenting the sample prototype to stakeholders, and for six-months time when you're trying to remember why you did what you did. As part of this it would help to keep records about the performance of the existing system so you can compare how improvements changed things. Ideally these will also link to the priorities/strategy you're working towards.
Two articles about UX principles you might find useful at this stage:
* "Is UX Design a Role or a Process?" - http://uxmastery.com/is-ux-design-a-role-or-a-process/
* Jeff Gothelf's "UX Skills for An Agile World" - http://uxmastery.com/beyond-the-basics-ux-skills-for-an-agile-world/
Keep me posted with how you go!