What is your understanding of 'nano coating'?

None of the above. It's basically a super-durable wax/sealant which can't even prevent scratches from 'bangla' wash.
Yup....that's about it....apply, level it (by removing excess), then let dry. But I find that the hot sun would be able to cure it faster....
Yup, there are coatings that you can DIY. It's actually NOT as easy as I wrote above . There's a bit of a learning curve on the proper application....not to mention you'd need to get rid of all those swirls and other defects on the paint BEFORE you apply the coating on - which is the most difficult and time consuming part of the whole thing.
If you can see those holograms then better send your car to a pro....unless you're willing to spend maybe a few days to a few weeks (depending on how severe is the hologram and how big is your car) doing it yourself. If you do, come back and I can try to guide you as much as I possibly could on how to do it yourself...by hand....