1. Utter rubbish. And I was using the same as you, a PDA running TT5. Nokia maps doesnt seem to get addresses very well, and postcodes...forget it.
2. Fine, but that depends on you. If you can text, you can do this just as easy.
3. Cant answer you about that, as I havent used TT on the phone. However, if you do want to use tomtom, you will have to buy a seperate GPS reciver, as they do not yet support the internal GPS on the N95.
Strong rumour is that TT version 7 is due out this month or November, and its widely expected to be compatiable with the N95. So if you can, wait