Those are some good suggestions. I might add a few myself:
1: If your device is rooted, you can separate the password that unlocks the /data partition from the PIN that unlocks the screen. This way, you have 4-5 digits that are quickly typed in... but if a thief decides to reboot the phone or power it off, they are facing the 20-30+ character passphrase... and most newer Android ROMs only allow 30 guesses before they do an erase.
2: Enable encryption of the /data partition. This is worth mentioning.
3: There is an app that will detect if the power button is pressed six times quickly, and send out a duress code. Forgot the name, but might be worth having.
4: Some ROMs will do some form of encryption on the SD card. If not, you can get an EncFS app, or BoxCryptor (which is a commercial/subscription version that uses EncFS as its base.)
5: Consider a backup program like Titanium Backup which uses a very reliable encryption mechanism (it uses a passphrase for a private key, and uses a public key for backups), and can save the encrypted backups to a cloud provider.
6: Consider a utility that requires a PIN to access some apps. For example, the app for a terminal and other rooted apps on my Android phone is PIN protected, FB and other apps are under another PIN, etc... so if a bad guy gets the phone while its unlocked, they might have access to the Web browser, but not the other parts. If they reboot the phone, they are faced with a very long /data encryption password as stated in #1.