After the number of posts listed in your post-count I am pretty sure you have read this if you have not please read it
Questions should be broken down to one question to one thread.
Search for "poormans install" for the type of install method you mention above.
If you choose an alternate boot loader to that included (grub-legacy) the seek the answers at the appropriate site to that bootloader, the information you receive will probably be more current, and there probably is an answer waiting for you there, in general though - choose the appropriate dropdown to where you want the bootloader to install - you can then use your bootloader to chainload the OS into life
Synaptic has a search function and a sections function, its really not that difficult to locate what you want, and yes it is thankfully very different from windows
and if you are already using KDE4 then you have qt4 libs bu default along with sqlite iirc.
Changing the wallpaper depends on the version, in KDE4 you just right click on the desktop and change the folder view options (in KDE4 everything in the user interface is seen as folders)
When posting, if you feel the need to have continued editing to the post, please write the post up in a text editor and when happy with it copy and paste to the forum.
In future can you use the one thread for one issue rule , as it allows a clear way for readers to see if your issue has been answered or not and makes for lighter reading too.