SilverMorty, if you're doing a mustache run, Kricketune is a necessity. Make sure it always has a move that involves sound.
Cantab, all of your challenges seem pretty interesting. I personally wouldn't like the six of one challenge, but that's only if I was playing, and you obviously wouldn't have put it down as an idea if you didn't think you'd like it!
For the pan-generational monotype, I'd be uneasy about using the starter as a wildcard, just because I think it'd always be the one to get you out of tricky situations that your type would struggle against, making it the "star of the show". Not sure what you could use instead, though... maybe another Pokémon of your chosen type from a random gen?
You don't get Trick Room until after the Elite Four in B/W, if I remember rightly, so it probably wouldn't be tremendously useful for a baby playthrough. Sounds like a pretty fun idea, though!
These are just my thoughts, but at the end of the day, it's you who's playing, so I won't be offended if you completely ignore what I've said!
100% of information in signatures on this forum involving percentages is false. If you feel as cheated by this atrocity as I do, don't you dare copy this into your signature.
Hold on... if this percentage was correct at the time of print, that means the actual percentage of false information is less than 100% if this signature is included. Which means that... no! I've become a slave to the system!!