1) Look up "portal" in FileMaker help and any training materials that you have. A portal to a notes table can be set up with two fields--one for the Notes text and one that auto-enters the timestamp, the date and time, that the related Note record was added in the portal. This can provide and endless list of notes entries associated with a given contact and each will be automatically timestamped when the note was added.
If you want, the portal can be configured so that the most recent note is listed first in the portal.
2) That one is a bit vague as to exactly what you have in mind and FileMaker can send emails, but cannot automatically receive emails, but you may find that is possible with use of an Email Plugin supplied by a third party developer.