I said "Other".
My V2 is debugged, and my V3 used to be. My V3 is proof that debugging isn't the only dangerous part of it. Undebugging is just as bad. I'm never going to debug my V4s, and I may get a second V5 to debug, as it's debugging works and fascinates me.
1. You can debug V4/.5, but it's in infinite hyperspeed, and you can't take care of your tama. V5 debugging works, as proven by Binary on Tama-Zone
2. Good: New characters, choice of characters, hyperspeed
2. Bad: Possibility of braking, glitches,
3. Hyperspeed basically is the only way to speed up your tamas growth, and goes about 3 minutes a second(?)
4. It's different for each version, and choosing a character just starts normal tama life in all without a 4, with the exception of hyperspeed.
One of the coolest things about hyperspeed is the ability to go through up to 10 or so generations a day if you feel like it.