Welcome to the world of Dynamo!
With regard to your concern about the ‘danger’ of Dynamo - the only danger is to your free time. Better programmers might correct me, but I don’t think Dynamo or the Python modules it uses run at a privilege level high enough to do damage to your OS , or even to your Revit install.
If Dynamo crashes (and it WILL crash…) just restart Revit & then Dynamo and all is well.
The is a risk of damage to live projects if you ‘play’ with Dynamo on them - NEVER try out some neat new Dynamo module on the biggest project in the company with the big deadline due next Thursday. BAD IDEA.
Always ‘play’ with Dynamo on small, test files first - so you can get the hang of what things do without destroying someones work. Even when you become and experienced programmer you should always test your code on small test projects first - never let untested code loose on ‘production’ work.
Your future ideal of ‘one tool’ is nice - but unlikely using Dynamo; it’s just not robust enough. But if you start looking at Unity… well there’s something that could grow into The Thing After BIM.
If you’re learning Dynamo I would stay clear of Python nodes. You’ll need to understand a bit about how Python works first - there’s plenty of free courses online to learn Python - but it has a steeper learning curve than Dynamo.
I have pretty much stuck with ‘vanilla’ (plain, no plugins) Dynamo - almost no plugins at all - and I really don’t think I have a need to delve into Python nodes to get what I want done.
Most of all - have fun playing with it!