@thebrickccentric The language you can use within the expressions is Javascript.
There are many online references available that explain them and where you can even try it, like here: w3schools.com
When I get more serious I normally use one of the many online IDEs like playcode.io
Like when i played around with the PRNG i had a go there.
https://playcode.io/616229/
Once I got it sorted there I ‘just’ modify it so that it fits into Flowlab.
About the obstacles, you just assign an incredible high value to them, then they will be avoided. Found an ecxel example where someone managed to do it without VBA, just basic functionality. That gives me hope 