Is there anyway to automate the creation of the "Actions to Run" within Rule Machine to eliminate or reduce the GUI part?
Maybe something similar to the dashboard tiles creation, where I can directly copy a json text in the advanced tab, instead of creating tiles one by one
Not exactly the same, but if you have an existing rule that you like, you can either clone it or export it and import the result. The export/import process uses JSON, though it's not intended to be human-editable (not that a Dashboard necessarily is, either, but those aren't too bad). That could save you some clicking if you're creating multiple similar rules.
Other than that, no: all rule actions have to be created using the GUI. If this is something you don't like, you may be interested in writing (or using--there are lots of community offerings) a custom app instead. These are written in Groovy, so you're able to write code yourself; the tradeoff, of course, is learning how. 
