there are probably other threads and blog posts on this.
1. You won't know the real effect until you test it. I am not terribly convinced that a Person vs. a Generic Email works better in all situations.
2. You did not tell us what sort of communication this is. If it is a generic newsletter, then just stick with news@email.company.com and have a proxy view on that box.
3. If it is intended as part of a sales initiated campaign, then it is ok to use Lead Owner Email Address, etc. so it looks like it comes from the Sales person. This is automatic, so you should only need to adjust the Owner in SFDC if the person leaves. I am not a big fan of getting such emails, but I'm not your audience.
4. Specialist newsletters: for example, my old firm had an alias for an actual person that we monitored using a middle initial to prevent that person's actual box from receiving replies. But if the person leaves, then you have to change this.
As for handling the transition, there are several factors:
- Tell people you are changing the address to X on Y day and to add the person to their contact list to whitelist you.
- Remind people again on the first send.
- Yes, your deliverability rates will drop and you will likely lose subscribers forever. Not much you can do about that. If they didn't care enough, then you don't want them anyway.
- Be careful if you are switching entire domains as that goes deeper. You will have to switch SPF/DKIM and should ramp up the send slowly.