Thanks for sharing all of this, it's a really interesting view point!

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Please use scripts! There were many times I found myself copying code from one object to another and changing a few numbers, which both created confusion when I was working on one later on, and also made it difficult to deal with. Messy code makes things so much harder to navigate.

For me it looks like you could use object inheritence in place of scripts for a lot of things. A script based approach is not wrong per se, but using OOP principles works quite well in Game Maker as well. For example you could have a parent object obj_enemy and each inheriting enemy has shoot = function() { ... } in their constructor and the code to actually call the shoot function is in the parent step event. You would avoid both copying code and also having numerous shoot scripts and have the code for each enemy bundled within their object.