What you're describing is exactly how the QT Framework works, it's cross platform, and the Ruby bindings already exist. It also enjoys the advantage of being open-source, although the QT Designer IDE is proprietary. So just as you can write and compile C# code for the .NET framework without Visual Studio, the task is greatly simplified with the native IDE. GUI work is well outside my day to day development however, so I'm not sure if it could be made to work with the Sketchup API. I'll defer such decisions to those better qualified to make them.

Sketchyphysics does have a time bar - but it does not display the actual time that we are used, as in minutes, seconds, etc. It uses frames. Each frame is basically a set of data derived from calculations. You can see this feature on the lower left corner when a simulation is running. It might be possible to convert the frames into what we are familiar with. But that would require some calculations I am not at the moment familiar with. You can search through the Sketchup ruby code index for time functions and such, and see what you can do from there. Assuming you are familiar with coding in ruby. -Chris

Sometimes it is best to start over, delete/replace a joint or explode/remake the group that is causing problems. Moving and rotating shouldn't be an issue at all, unless you moved joint off center in wheels or anything. Scaling can go nuts tho, my advice is to scale only internal groups/geometry and not the external groups, or if you already scaled try exloping/remaking the group to reset it (this is also very important with static-mesh as it doesn't like scale). Also it's always best to upload the problematic model so we can see what is going on.