Is a PIN lock screen inherently more or less secure than an app lock program? The two ways I see to secure an Android phone is through a PIN lock screen or through an app lock program (Password is too inconvenient and pattern is insecure for various reasons).  The lock screen has the advantage of keeping someone from the phone altogether, but an app lock program can allow me to use basic functionality while locking the apps that I choose such as Email or Package Installer.  

Is one option easier to hack/bypass than another?  Let's assume that the App Lock program has a helper app that prevents it from being killed (although how well such an app works is worthy of being discussed in an answer - point being it takes a little more work than simply going to task manager and killing it). 

I am primarily concerned about data on the phone. 

I know that ultimately I cannot rely on either method to secure the phone indefinitely, but to only secure it long enough for me take various actions such as remote wipe, change Google password, Exchange password, etc...

I'm running Gingerbread 2.3.6.  For what it's worth it is rooted and has ClockWordMod recovery.
You could always Encrypt your device. 

Depending on what phone you are using will determine the method or even availablity of this function.

It takes time though and you should do it with about 80-90% battery.

Also, I beleive the fact that your phone is rooted, makes it less secure - assuming the thief/person who picked up your phone (assuming that it was to be lost). 

As long as they can access the internal/external storage, they can bypass this.