Eobet,
Not 100% positive on what you’re trying to ask for the arc question - when you say you want to “edit” the arc without the center, what kind of edit?
Regarding the trimming issue - my bet is you’re just running with the default tolerances which are too loose. I attached a screen shot of my tolerances. Try updating them in the contruction settings, specifically the fitting options.
Let me know if that helps.
