Switching from Gravatars to Local Avatars

After assessing the Gravatar vs Avatar situation, I've decided to go with the local solution for my community while it is still small enough to pull it off easily. Andrew and drmike's opinions in other posts weighed heavily in the decision, but I also assembled what I believe to be the primary issues for my site:

Avatar
+ Local control/storage/management
+ Faster page load (theoretically)
+ Could mine database for photos (Import to CRM, directories, etc?)
- Only useful to one WPMU network (not major since my users comment primarily on each other's blogs)
- WPMUdev avatar plugin isn't fully integrated with BuddyPress (?)

Gravatar
+ Works lots of places, basically ubiquitous among blogs
+ Effortless for users *once set up*
+ Blog visitors more likely to have Gravatar than to have an account.
- Extra steps in signup process = friction = lower conversion
- 3rd party site registration during signup = confusing/suspicious
- Question of security (Are emails shared/secure?)
- Unlikely to be adopted by big social sites (Facebook, Twitter, etc) due to high business risks (dependency) without much benefit.
- Privacy concerns (Is Automattic tracking users across sites? Probably.)
- Major site-wide UI component reliant on small-ish 3rd party (Change in TOS? Cease of operations? Then what?!)

So, given that I've decided to migrate to local avatars using the WPMUdev plugin, I have a few questions:

1) Are there any "gotcha's" waiting for me on the path?
2) If a visitor with a Gravatar submits a comment on a blog, will their Gravatar display?
3) Andrew, can you expand a little on your note: "Our avatars plugin should not be used with BuddyPress." I *do* use BuddyPress and BBPress.

Refs:
https://premium.wpmudev.org/forums/topic/avatar-plugin-and-gravatars
https://premium.wpmudev.org/forums/topic/avatars-vs-gravatars

Useful post/comments from publishers' perspective:
http://weblogtoolscollection.com/archives/2009/08/17/why-is-gravatar-still-not-mainstream/