Understanding Welcome Email Feature

I have a few questions with regard to using the welcome email feature:

What's the difference between creating the welcome email within the List Dashboard and the Email Dashboard?
I am using Community Builder and programmed sign-ups to be added to a specific list when registered. Will this trigger welcome emails in AcyMailing when users are subscribed this way?
If I create welcome emails, will existing users in a list get the welcome emails or will it only be anyone who subscribers from the point they are set up
If I want to add users to the welcome funnel where they receive one or more emails, I gather it would be best to use automation instead of the welcome email option. Would the be correct
Speaking of automation, what trigger would I select to send an email to a subscriber, for example, 2 days after they sign up?

Thanks!

there is no difference at all
yes, if your members are subscribed to the newsletter list during the registration, they will receive welcome email
only new subscribers will receive welcome email
you should use follow-up email feature in this case
follow-up emails would be better in this case as well