Hi again,
Peter is right - though only one entry/do/exit operation are allowed, several actions can be carried out in each operation.
So I mostly figured out how to get what I want. The steps I took were:
- Select the state you want to add the operations to
- Go the "Features & Properties" window
- In "Features & Properties" select the "Behavior" tab
- In the "Behavior" tab, select the operation you want to add, e.g. entry and write in essentially a title in the "Name/Comment" section of the entry behavior
- Then go the "Behavior Properties" window and under the "Behavior" tab, in the "Behavior" textbox, enter all the numerous actions you want to execute in the entry operation
- Check "Show Behavior in Diagram" box, hit save and voila, all the actions will show up in the entry operation, exactly like in the picture I posted in my question.

The only issue now is that the entry/do/exit operations are not showing up in the correct order in the states, so I will be trying to figure that out next. If anyone has any clues about that, please let me know.
I hope this answer is useful to someone else as well! Thank you guys for your help!