Hi and welcome,
I wrote a post about GTD with dynalist here too: My latest GTD setup in dynalist
Dynalist is great for GTD but your system can become overcomplicated like you say as there’s so much freedom 
You’ll see right at the end in that post someone asked me for an update to this and I outlined my slightly modified simpler system which I’m still using
If you want to be decently productive on mobile check out quick dynalist too for widgets and quick send to anywhere
Good luck!
Stephen