Joining Date Table to Table with Multiple Date Field

I wrote this article that covers most of your questions https://exceleratorbi.com.au/multiple-relationships-between-tables-in-dax/

as a general rule, I prefer to turn off the auto generated PBI date tables. My view is these are for beginners to make it easy to get started (JMO). It may or may not change the total size and refresh up or down. Chances are you won't need a calendar table for all date columns, so net net, it's probably better to do it yourself. 

another approach is to create a new fact table containing all your dates in the format

foreign key;

date type;

date;

set the relationship back to the dim/fact table as bidirectional cross filtering.

you can then join the new table of dates to a single calendar table. 

as Marco Russo always says, "it depends".