First, you CAN save cue points. I'm not sure what you're doing - if you could provide a step-by-step or screen capture that would help.
As for the : in track titles - I think it's generally a bad idea to put special characters in fields where they don't belong, but it should warn you rather than replacing it. We've already noted this with the engineers.
You also didn't provide any information for "I changed every title of a song ... and everything's lost," can you elaborate?