This is how my current dev version looks (This is running on Kodi 16.1 on Ubuntu).
I'll update this post later with a screenshot of how it looks on my Laptop (again Kodi v16.1 but Win 10)
Looking at the code for the version running above, I can clearly see that screen presentation has been something I was going to address, as there is code in there to get the screen width and find the centre. Possibly my maths was having an off-day that day, as having got a centre point, I don't use it for calculating the offsets for the text although the code
is written to use offsets.
I will have to get back to this and try and figure out a better cross-platform display solution. Hopefully Kib will be able to give me some pointers. I have half an idea about how to improve it, but it would necessitate writing a whole new skin for the window (limited skill-set here to do that !!) and re-writing the output routine accordingly. I think it's do-able but it may take me some time to get right !!!
About your point of keeping multiple sources.
The add-on can operate two ways, it can either completely ignore your sources.xml file and just delete any references to http://, rtmp(e):// and plugin:// which removes pretty much all streaming links, or it can use the sources.xml file and ignore any paths found within it and delete everything else. If you have the same path defined more than once in your sources.xml then it'll list it however many times it's defined. Your screenshot would appear to suggest that some of your Kids stuff is in there twice.
About bookmarks!
The add-on has a setting to exclude any files with bookmarks set. I'm probably going to remove this at some point as BatterPudding & I appear to have lost contact and he wrote most of the SQL stuff. In the original version bookmarks worked fine, but as the SQL has necessarily expanded as DBC evolved, we (I) came to a point where it just trips up the add-on and although I spent some time trying to correct it I was unable to at the time. Probably I'll revisit it though before I remove it and see if I can figure it out.
Finally, there was an issue a few posts back with paths with ' in them - Imagine, people naming paths correctly !! That's been fixed and there is a link to dropbox with an updated version as I can't push it out through the repo
Whether or not this also addresses any of your issues I'm not 100% sure, but it does include things like notifications on start-up, progress box if there is a lot to remove, re-naming of a path in the database and removal of a specific path in the database (both of those last options are one shot deals and should be used with caution!!!).
The dropbox version should be 0.5.6 and should install from zip and update as normal.