The ability to import just the BMP background is on the to-do list. For now, you can use the AutoMux utility. It's simply a one-click process. As for changing subpicture highlights, it's not that simple. They are embedded in the VOB, no software I know can change it without first extracting it out for editing. If you can find a software that can do that, let me know.

Where are you lost in the instructions? Anyway, look in the attachment, I've done everything for you based on the instructions. All you do is copy and paste your video content over. Import my files as project 1 and your modified project, that you have splitted and created the programs, as project 2. In project 2, in VTS1 domain/Domain Content pane, select the second block (pgc1:c2), scroll all the way to end, hold Shift and select the last block, and choose Copy. There are 71 blocks to be copied. The first block as you say is the unwanted 3-sec part. Switch over to project 1, the same VTS1 domain/Domain Content pane, press Ctrl-A to select all blocks and Paste. That's it. Hope this works out for you.

btw, you may want to take a look at at TMPGEnc Dvd Author - it is appropriate for a beginner level.