Python is often required, but most of the time Python scripts do pretty simple and explicit stuff. Some of them (Cyan's xAgeSDL scripts) are documented already, and more will come eventually.
So in the end you'll be able to setup your logic fully in node trees, and only use Python as "extra" nodes which you will connect with the rest.
Don't worry, I believe with good tutorials about node trees and what each Python scripts does, you'll be able to do all your puzzles in node trees and treat Python scripts like special nodes, without headaches.
Once you get the hang of node trees you'll realize most of the time they do one of those two things:
detector(s) => responder(s) => other objects (animations, sounds, etc)
detector(s) => Python => responder(s) => other objects (animations, sounds, etc)
Which translates as:
DO action WHEN event
DO action WHEN event IF condition
Detectors are simply clickables and regions. Responders are a "todo list" you give the engine (run an animation, play a sound).
What Age builders need is mostly examples and tutorials of the most common interaction, so they can get familiar with the nodes and understand which nodes are used as action, event or condition. Once you're good with that, you can start creating your own puzzle.
These tutorials will come eventually, and some of them require a bit more standardization to happen so you won't have to bother with technical details (like how to write SDLs, how to do linking without having to worry about save corruption, etc).
(Some of the most complicated puzzles (think Gahreesen's power room which require timing and multiple connected levers/animations) will require their own Python scripts, but those can be written on-demand by people on the forum. I expect most of the time you'll be able to create puzzles without custom Python scripts though.)