Not completely following you.
When entering a Form, you should see 3 tabs> Details, Headings, Gallery. You will go to the Details tab to enter each person and their census info. You can also go to the Gallery tab and enter a media object. The Heading tab is pre-populated with the census-specific headings (attributes of the Census, not the person). You can add this info (I have never done this as I include a media of a snapshot of the census image).
If you look at the Person view, you can see the Source (specific census) and the set of citations (as you showed). You get one citation for the reference to each Person, one citation for the reference to the Census Event, and one citation for each field (like age, sex, …) of the census you completed. At least that is what it looks like to me. I never looked at this before.
I have never seen a crash. Can you open a Terminal window and start Gramps from there? That can provide a dump of a crash.
NEVER merge citations. This will completely mess up the Form. There was a discussion recently on this specific issue.
See Corruption when opening FORMS data in PEOPLE screen for discussion on Forms and Citations.