I think I made some progress.. I have gone through this thread - Custom App is working from Gateway URL but not if we are using Reverse Proxy , and based on Tejas Chouhan response, I removed the Component name from LPD_CUST
Now when I load it, the initial namespace error is gone, but now I'm getting another error.
2016-01-21 16:01:05 Application initialization failed due to an Exception:
TypeError: Cannot read property 'TextView' of undefined
PS: This app is working perfectly fine as standalone UI5 app (deployed as BSP).. The problem is only when I try to open from Launchpad.
Thanks!