1- It applies on local commuting. On long tour chain doesn't get lose in one go. Still its better to check it after each 500 km. The sticker on chain cover tells you how much lose it should be.
2- Seat ko kharrka ke dekho if it sounds. You just need to open 2 screws near rear indicators. seat will come off by pulling it then you can examine not much expertise required.
3- Don't worry itni jaldi kuch nai hota isko don't take it on your nerves. But don't make it a habit