Well, you install the ~SETUP-TDD.TP2~ #0 #1 // ... component at the end. Unfortunately, I have heard that some of the TDD kits don't work as they are supposed to work, I don't know the specifics on the Dragon Slayer kit, so it could work.i can see something about a mod Kit Remover but nothing about adding them
You get the new splash screen by installing the new GUI, with the setup-gui.exe that is in your game folder after you installed the BGT. As you can see the version of the BWP that you used, already installed and uninstalled the setup-gui, cause of a mistake, so you just have install it again, but first TDD kits and then the GUI, and then perhaps the Widescreen mod...