1. Regarding your first questions - indeed there seems to be a problem with changing the Assgn text to a preferable one, since it should be manageable using the following:
I have forwarded this to our developer team for further investigation.
2. I am afraid that the default step in the percentage increase/decrease is the one that is currently implemented and it cannot be managed via a property or settings.
3. You can change the needed format, using MonthView-WeekHeaderDateFormat
properties and set the preferable format.