Yep, so that’s a good point, if you are doing a lot of relational data it’s probably best to use SQLite. And if you don’t care about testing in a browser then even better, because that won’t be a factor for you.
As far as persistence, I was only bringing it up because localstorage is not safe on mobile, as the OS may delete it when it detects the users phone storage is getting full, yet it won’t delete SQLite. This makes the ionic storage module really handy for simpler storage because it handles all that for you and you just save and load json. In your case though as you say probably not a good idea.
So then yes, just use the SQLite plugin with Ionic Native and you’ll be good to go! The regular ionic native docs explain how to use it, there’s not much to it, just write your sql queries.
Unfortunately things like creating and keeping the database updated is up to you. In the past I created a database creation service that handles initialization and modification of all tables and had it run on app startup. I don’t know of any migration frameworks for sqlite, so I believe you just have to handle it yourself. Generally I just don’t store that much data on the device, instead it’s mostly on a server, so my SQLite stuff has been lightweight enough to just handle it myself.