A1: Yes it will, however it doesn't provide very good cooling. You'd be far better off with either a Zalman CNPS8000 or Silverstone NT06, in a Sugo SG01e or SG03 case. I recently upgraded from an SG01e to an SG03. I'm running an HD2900XT and it doesn't go above 60C in games. Amazing cases. Those coolers would also open up the option of adding a Q6600, however make sure you grab one of the new "G0" steppings, they run cooler.
A2: In short, no. All three cases take full ATX PSUs, and I would recommend you get a good PSU anyway, not just for it's efficiency, but for it's silence and also the cooling it would provide through it's fans.
A3: Well, looking at this week only, there's the X1650XT cards for £45. These are brilliant cards, somewhere around 2-2.5x the speed of your 9800 Pro, and at a great price. I'd really recommend picking one up at the very least, you won't regret it.
Now, my turn.
Q1: Why are you buying an AMD AM2 system over an Intel Core 2 system?
Q2: Are you looking to do any overclocking?
Q3: Is the card reader necessary?
Even if you do stay AM2 i'd recommend swapping that board, there are much better ones for a similar price, like the nF-M2 nView.
A2: In short, no. All three cases take full ATX PSUs, and I would recommend you get a good PSU anyway, not just for it's efficiency, but for it's silence and also the cooling it would provide through it's fans.
A3: Well, looking at this week only, there's the X1650XT cards for £45. These are brilliant cards, somewhere around 2-2.5x the speed of your 9800 Pro, and at a great price. I'd really recommend picking one up at the very least, you won't regret it.
Now, my turn.

Q1: Why are you buying an AMD AM2 system over an Intel Core 2 system?
Q2: Are you looking to do any overclocking?
Q3: Is the card reader necessary?
Even if you do stay AM2 i'd recommend swapping that board, there are much better ones for a similar price, like the nF-M2 nView.