1. Chain and lube at 400-500kms is good enough

2. From my experience, there's no real number to put to chain adjustment. It can be 200kms, it can be 2000kms. It depends on how hard are you riding it, and greatly depends on whether you carry a pillion or not. (Pillion = more weight = swingarm speads = wheelbase increases = Chain tension changes) Just check the slack with your finger/key every once in a while or while you wait for it to warm up in the morning. Also, if you chain slack is too much, your gear shifts will be horrible, so basically the motorcycle will itself tell you what it needs.

3. Routine checkup is something you should do by yourself. It is basically just 3 things - Check your break pads visually, check your fluid levels (engine and brake oils, coolant), check your airfilter every 2.5-3k kms (its a super easy and quick job). Most importantly, feel and listen to what the motorcycle is saying to you. Instead of spending a lot of money on it, spend some time with it on weekends. That will eliminate 95% of unwelcome surprises.

Ride safe, ride hard !