q2: As I told you there's no such a thing as a 'program directory' in Linux. All the files of a program are spread out across the file system.
To make it clearer I'll take Synkron as example. It's a small Qt-based synchronization utility. The package contains the executable file that is installed in /usr/bin/, icons that are installed into /usr/share/icons/synkron, documentation (/usr/share/doc/synkron and /usr/share/doc/Synkron-version), and .desktop file (/usr/share/applications). The latter is a text file that represents a program in application menus, on desktops, panels, etc of different DE/WM (makes the same work as windows' shortcut). In short there's no "Program Files" folder you're probably searching for.
The information about the installation you receive at the end of every installation no matter what program you use for that. In your case if kpackagekit in the end didn't say anything about installation errors, missing dependencies or something, the installation was successful.
I'm not aware if there's any logs for apt and dpkg command or their front-ends as I never was in need of those. To find out if a package is installed you can use apt-cache. Here's
a quick how-to for apt/dpkg commands.
Either you can just use the package manager (it might be called Software Center or something similar - I don't remember the exact name) provided in Kubuntu and search for the package of interest.
The simplest way to find out whether a program (not a package) is installed or not is to press Alt+F2 in KDE, that is the default DE in Kubuntu, and to start typing the program name. It should appear there if it's installed.
Regarding the other question please explain what do you want to do with that file? If you want to change the colors you just have to edit the .dir_colors in your home directory. If it doesn't exist just create it. FYI the files starting with dots are concidered as hidden files in Linux. By default file managers don't show them. The ls command needs argument '-a' to make them show up.