1. the header pipes blue this bike, get some blue-job and wipe your blues away! or you could wrap it with exhaust wrap, or get heat shields. adjusting your idle mix screw is in the tech section, the bike pops on decel out of the box...
2. 3k miles from the manual, whenever you feel like it realistically...
3. replace what ever you can find that's higher quality, for example I replaced everything I could with a ratchet and some sockets/screw tips, left what I couldn't in the bag..
4. lot's of info on this in the tech section, I personally just count every 100 miles or peek in the tank every now and then...
5. get the schematic guide for the bike (tech section), then you can search the net by part number and find whatever you need and decide where to order from, or try your local suzuki dealer.. if it's an easy nut and bolt you can try your local hardware dealers..
don't be like me and go tinkering with the engine and stuff (unless you know what you're actually doing) and end up with a sloppy running bike (that still rules)... I'll know what I'm actually doing soon enough though