Interesting approach Diego — thanks for sharing it! I’m not sure I’d want to place product value proposition there actually, but would instead make sure it was clearly spelled out on a Lean Canvas instead in more detail. It sort of hangs together though as you’ve got it and the idea is sound. :)
I’d probably consider keeping those things, but moving them off to another artifact that everyone agrees on (Lean Canvas, Business Model Canvas, etc.). In general it’s really hard to write a product vision, and state your desired business impacts at a high level, so I’d keep it simple, but you really really need that stuff (problem, solution, competitive advantage etc.). I’m just not convinced that goes on your roadmap though, but it needs to exist. You do need to remind people what your mission is though on every roadmap — folks tend to go straight to features and buttons because it’s fun and familiar, without defining success first or aligning to goals— which tends to result in low impact towards the vision and goals— that’s the only reason I tend to always keep it up front and center: as a reminder.