Is Android Gmail safe from other apps?

Question

By "safe" I specifically mean: safe from potential (unauthorized) access of other entities of Android system, such as third party applications.

While it's clear that no app is safe from users (in this case, installing apps from suspicious sources) acceptable safety would imply:

• safe connections (SSL/TLS) to and from server
• password used only once, in order to obtain token, and never stored
• stored email messages encrypted or another way to disallow any other entity on the OS from viewing/altering its content