cut out characters : symbols vs templates

I noticed in the animate pro tutorials the ballerina in the video is set up with symbols??

How does this work? If symbols are limited to that particular project
I won’t be able access them if I do a ‘save as’ and create a new project?

I’m thinking since symbols can be updated this would be a better option if I want to continue updating my character later? Where as with templates each one is it’s own separate thing.

Also iIf I use Symbols instead of Templates to save character animation clips
will doing this break the animations I already created using that symbol?