Does it work with any external controllers over BT?
There is nothing in the settings which would allow you to map controls, so I'm going to say no.
I've been playing this game since release, bought it within an hour of it coming on the app store. I totally love it. It's exactly (if not better) than the original game on the Playstation. The only time it lags is when driving between islands, but when you consider that on the Playstation you had to sit there whilst it said "Welcome to Staunton Island" etc for a few seconds, I think a split second jump is a massive improvement.
Apart from that, playing on the iPad 2 I have absolutely no performance issues and the graphics are perfect, no impurities like you would have got playing on an old low resolution TV through composite cables like we used to on the Playstation. Loads of cars even have 3D engines too which I can't remember being in the original game either.
Here are some screenshots I took last week. (I'm a lot further in the game now)
These vehicles are a lot more common than the original game too. I remember playing the game every day for weeks before seeing one of these to take to the import/export garage. Now they are in plentiful supply.
To those wondering, there is no way of cheating in the game. Also the only other thing I've found a lack of is I can't control the hydraulics in my Yardie Lobo.
You can freely place all the buttons on the screen wherever you want, and you can also use the analog steering for driving if you prefer steering that way.