1. Look at the sticky in this forum about maps and navigation. Plenty of different options, depending on what you are looking for. You can use Nokia's maps free but without navigation, or you could use google maps, but would need datat etc.
2. Yes, there's a Nokia apllication for that included with the phone, but the installation files are located on the 2GB msd that comes with the phone and automatically install on boot (you need to copy that card into your new card if you upgraded to a bigger one). In my tests it worked pretty well.
3. I'm not sure about the barcode scanner if any different than the N95, but it def works with 2D codes (look for those around, you basically point and it retrieves the info, which could be internet address etc. and you could load the link that way on your phone). Kind of fun, could be convenient sometimes. As for regular barcodes, not so sure, but either way, not really useful imo.