1: I totally aprove of Output file name managing. Dates, Autonumbers, even the 'Limit maximum recording time' options could use a numbering feature when you are using the 'Create new recording and continue' option. This could be handy. +1
2: You seem to want to edit your recordings in the mix. That kinda stuff only happens in techy TV newsrooms and when beatboxers use a soundstation. It would be more sensible to just record what you want in one big blow, then edit it with all your negitive/BnW/whatever later with another program.
3: Multiple recordings sounds like the way to go, but then again I have no idea what end you are trying to acheive with so much sporiadic alterations. I was reading a post earlier that someone was trying to use Debut to record from multiple cameras for the sake of home security. Unlike your question, they didn't want to just switch from camera to camera, they wanted all of them.
Again, I don't know why you want to switch about like this. But it's a good idea for say, livestreaming.
Ps. If two or three suggestions are made for something, the developers will look at it and go 'Hmm, ok. Could be usefull but isn't going to benifet us very much'
If one THOUSAND suggestions are made, the developers go 'Holy! This is really popular, we should do this and get some good reputation with our consumers!'
The moral of this story is; if you want to suggest something, bloody give it to them.