How to protect my Google account credentials on my Android phone?
Using a free service like Android Lost, you can remotely control your phone from a web browser. You can wipe it, locate it on a map, read sms'es, take a picture remotely etc... to ease your concerns regarding security.

While not directly an answer to your question, it might be a viable solution.  Not storing your Google credentials on your Android smartphone and accessing Google services through the mobile web brower is not only very impractical, but also sort of defeats the purpose of a modern smartphone doesn't it ?