Hi there
Its been a while since Ive used Bubbleup. However I have just installed it to test it on my 2013 Sony TV - it worked fine straight away. If it doesnt work for you, check you TV's network setting.
I would not advise you to use your mobile as your primary device for a DLNA media server - you are in for a world of hurt and pain if you do. Look for a cheap Synology NAS server is my advice.
It is not possible to restrict which files or folders to view when directly connecting a HDD to the TV. It will display all media files - so move that porn elsewhere
As the TV is a DLNA Renderer and not a server, you will not be able to stream from a directly connected HDD on the TV to your mobile.
As I said above, a small bit of investment in a proper DLNA Server (i.e. A NAS server) or even a directly connected media player will save you a lot of hassles. Asaying of mine is - Do it once, Do it right.
Cheers.