Re: the e-mail, you could view that approach as cowardly or compassionate depending upon your perspective. I promise he's not an expert at handing out separation agreements, so he may have thought that face to face would be more painful for you. That would be the glass half full way to look at it.
WRT telling parents and friends, I've gone through this with my sister and a couple friends this year where I was on the receiving end of the declaration. You should be prepared for the fact that the other party probably won't know how to respond at first. There is nothing wrong with saying that you didn't want this, or that you would prefer to stay married, because otherwise the first follow-on question they are likely to ask is if you're happy about it or not, as they'll be trying to figure out if you're leaving him or the other way around, or if it's mutual. I do think you'll find people will be more compassionate and supportive than you might expect once the initial shock has worn off, and that support can be very fulfilling longer term.
I've confided in several friends about my sitch and those relationships have definitely grown stronger as a result.
Acc
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015