I’ve had similar issues getting Inform 7 to work on Ubuntu 18.04, and have installed the dependencies manually according to the linked forum posts (many thanks for those).
I’ve installed both the Ubuntu 15.10 and Debian Wheezy versions and they both load fine, however when I attempt to load a project, the file browser shows everything greyed out (read only?) and I cannot open any file or browse to any subfolder. I’ve run Inform 7 as root (isn’t everything always a permissions issue on Linux!), and get the same experience.
If anyone can throw any light on this issue, I would be very relieved to get I7 working. I have a VM running Ubuntu 16.04 (which was surprisingly hard to find a Vagrant box for) but it’s not an ideal situation.