Application to export details about system set-up

So here' an idea.

When one upgrades Ubuntu it's usually possible to do it from the OS without re-installing. Trouble with this is the possible left-overs, extra files, etc...and any mistakes made in transition.

But thing is, it really is preferable to just start fresh, from scratch, by wiping the OS and starting new.
But if one does this, one loses all those little tweaks, the programs, etc...and it's hard to do everything all over: especially when in Linux something won't work, one hunts it down, fixes the problem...barely finding a solution: but if you upgrade you may end up losing this.

What would be nice is a program to track all the programs that have been added, and a way to manually type-in settings as well; then before an upgrade it could export the files (which should be understandable to normal human beings as well) to re-import them on the next install and pass them to Ubuntu to fetch the latest versions of those packages...while leaving the manually-entered extras (urls, one's own descriptions/advice etc.) for the user to read. A personal example is when I use Window's programs on Ubuntu: at first I had to figure-out how to use symlinks to link them into the Window's partition to read their own files, (I know most people don't do this, but I didn't want to install more files and fight to keep them in sync between OSs).

Here's another consideration: when upgrading between versions one might then have, still, the old settings for taskbars etc...the icons, applications/etc. menus, and so on...but it may have changed and new features could've been added/refined etc.. It would be desirable to overlay the new and old with an offset to transfer what customizations the user had from the old to the new, and to take stock of what's in the new and decide what to leave, what to change, etc..

I'm just thinking here guys: I can't program, but I can give ideas. Hope something here will be useful.