Answer 1:Problem #1 - Too little RAM
Problem #2 - The CPU and GPU are far too weak to run even basic iPhone games
Problem #3 - No Multitouch support crosses out a lot of iPhone games which require gestures
Problem #4 - The resolution is much, much lower - 256x192 per screen will require resizing of graphics
All in all,
my number one problem would be the platform itself - there's too much of a specs discrepancy between the two.
Answer 2:a. One magician, one genie and one shaman. Their function would be trying to conjure resources that aren't there.
Seriously though, provided the game would theoretically be able to run on the DSi, I would probably put 15-25 people on it - 2-4 designers for touchscreen-specific functionality conversion "on-paper", 8-16 programmers to port the game and 3-6 3D Model artists to adjust the models and textures if necessary. They could all playtest the game while at it - alternatively I'd hire additional few lads just to play it. Let's face it - iPhone games are not huge, porting them should not require a huge studio.
b. A few months, provided there aren't any hurdles on the way.
Keep two things in mind though - I'm not a professional coder, I merely have fun with homebrew every now and then. That, and as I said, the DSi is far too weak to pull off most iPhone games - you can port DSi software to the iPhone but not the other way around.
This post has been edited by Foxi4, Thu, February 21st, 2013 at 19:41