I haven't seen any issues using Phonex all these years... News application does connect to web but I disable it and notice no problems.
Out of curiosity have the ones that reported that their web connection is always active, have you really paid attention to it before you installed Phonex because with sense weather always updating and email checking for updates I noticed my unit was always connected to data out of the box.
Without using a patch or software to disconnect data it does not disconnect on its own so once it connects it stays connected so I think you are blaming wrong thing for data connection being active.
And as for the end button not working, this has to be a setting because I hangup all the time with mine and it works fine. Check settings for lock hard keys isn't checked...
Try this cab to disconnect web after 2 minutes of non use of data connection or try bandswitch
Oh yeah forgot to attach cab to remove 2 minute data fix in case you decide to change settings back if you use Bandswitch to avoid settings conflict... Uninstall original 2 minute fix from ADD and REMOVE and install Remove Data Connection 2 Minute Disconnect cab and reboot....