Welcome Mikey! Wappler can do everything you have listed. You can connect to any data source whether it’s a database or API. It will take some time getting used to the workflow but I’m sure it will be worth the time spent.
There are plenty of docs and tutorials but as you can see it’s an active community here so we all try to help out where we can.
You can use another Bootstrap 4 template. You may find parts which need a bit of playing with. See this thread for more discussion… Recommendation for a good Bootstrap Admin Theme