Yup
Nope, as this is almost impossible to get right (due to the weird dependencies that the old cura has, and Ubuntu being very very bad in packaging)
Someone made that once. I have no idea why. It's pretty much our slicer, but then without an interface.
If only. This makes the assumption that certain dependencies can be met at all / that there is a 1 on 1 conversion from one version to another. This is quite often not the case. We depended on a number of pooly packed / handled dependencies, making it impossible to let the OS handle it.
Yea, download the 15.04.4 version from the site. That worked for me (both Ubuntu 15.04 and 15.10)