Eh, (2)/(3) can be a pain for web mail accounts. For instance, I couldn't send patches to LKML through Gmail directly, since even for plain-text emails it wants to rewrap long lines itself. To get "git send-email" working through it, I had to wade through a bunch of outdated info to find the right method.
Even now there are persistent downsides: every email through "git send-email" contains my original IP address for everyone to see, unless I use a VPN service. Also, since I'm not a right-thinking person with a 'real' client-based inbox, I have to fiddle with the In-Reply-To and References headers by hand, if I want to include a patch in a reply to another email.