Issue:
'Label as' is hidden under “More'

Fix:
More → Switch to advanced toolbar

Ref: https://support.google.com/mail/answer/2473038?hl=en

Settings gear icon → See all settings → Hover actions → select “Disable hover actions”

Ref: https://support.google.com/mail/answer/2473038?hl=en

When creating the filter, use something like below in the “From” field

(email1@host.com OR email2@host.com)

This will do a search for

from:(email1@host.com OR email2@host.com)

• To enable keyboard shortcuts:
  Gear icon → Settings → General → Keyboard shortcuts → select Keyboard shortcuts on → Save Changes
• press ? to display the keyboard shortcuts in gmail
• e - archive
• # - delete

• https://support.google.com/mail/answer/6594 - lists all the keyboard shortcuts.