Very good runs, I love how your videos may not show the best paths, but always some new stuff of your own that usually simplify the hard tricks but still get a really good time. Keep it up, I definitely look forward to seeing more of these.
FYI: The super speed + wall-hit trick in RUC is easier done by activating the ss much earlier before you do the wall-hit.
Also, I am currently working on an MBU in MBP complete speedrun, and have 60/61 levels currently recorded. I plan to release the video on 1/25/2016, exactly ten years after the release of Marble Blast Ultra onto Xbox 360.