Mail vs gmail vs Yahoo!Mail

[Glider_Guider]

There is a built in email app on my LG Optimus Zip (Android vers 2.3.4)
I subsequently downloaded the gmail app and the Yahoo mail app.

I suspect I am wasting my precious little memory by having 3 email apps.

Obviously I could uninstall the gmail and Yahoo mail apps but
if I prefer to use the Yahoo email app and delete the gmail app...
1. Will my Google calendar sync no longer work?
2. Will the built in email app continue to run even though I'm using Yahoo mail?
3. Is it possible to uninstall the built in email app?

 

[clark71822]

Unfortunately, it's not possible to uninstall either the Gmail app or the multi-account e-mail app on this phone, since the only way to remove factory installed apps is to root the device, and as of now, there's no known method to root this phone.