Hey @Ash08,
You know about Petter’s book bubble performance, so you probably also know about his other book on Bubble security?
That will probably give you a massive amount of help towards keeping your app secure. Unfortunately I’m also too new to add any real value here other than referring to others and posts etc. so I suggest the book “The Ultimate guide to bubble security”.
Also I started a discussion post a few days back about responsive design that might help, there have been some very interesting responses there I’ll drop the link.
It sounds like a nice project you’ll be working on albeit a tough one especially for your first app. Hang in there though the forum is full of help. Good luck