Can only say what i avoid ...
the do nots ...
Use the picture editor to do graphic work. U need it to import and to set image points.
Delete the object holding a the first loaded sprite. Feels to me like all the other object sharing that sprite, refer to this base one. And deleting the first one feels buggy. Spared me a lot of crashes.
Copy layouts, move layouts, change the events sheets coupled to a layout. Dont.
Delete private variables, change private variables text/number.
Delete image points.
Make triggers and conditions in 1 event. The triggers should be always on top of the tree, the conditions should be sub events.
If you access private variables using families, make sure the private variables are at the same position in each object.
Copy objects between layouts.
Undo on switches in the layout editor. With switches i mean things that are there or not. Like bringing back a deleted behavior. Undo a deleted object. Undo deletion of a variable. Undo deleting/adding.
Copy and object to another layer, and delete the original object.
Change layouts in an event with a zero time.
Leave 's p a c e s' in objects names, layer names, even behavior names.
Now if you track all this back to what all this has in common. Then you will notice most is about The events not updating with changing objects in the layouts. Or the other way.
To see this work.
Change an objects name in the layout editor, go to the events editor, and see the name is changed there too.
In other words, the events sheet updates towards changes made in the layout editor.
In some situations this dont happen. And that will be a crash.
And i think, besides the upcoming bug reports about last release, thats about it to be CAREFULLY with. Since last release construct seems very stable.
I say: go ahead. But accept that events and actions still can change. Meaning, a events sheet could still be not compatible with a next release.
Have fun.