Lets start with the merge.
You cannot delete anything without changing commands.
I assume that your DVD is split on a Title. First DVD has menus and first half of title, second has second half of the title only.
When you do merge, merged DVD will add all VTS from second DVD plus VTS with a default navigation menu.
Default menu has choice of two DVD to play. If you click on first DVD it will go to a menu in that DVD, assuming that how the first DVD was working before.
If you click on second DVD in default menu, it will start to play second half of the title, assuming that how it was working before when you inserted second DVD into the player.
You can use Debug to see how merged DVD functions.
If you want to bypass default menu, you can change command in First Play to jump to a Root menu of first DVD, which will get you to your main menu.
Easy way is to right click on VTS which contain Default menu and click on “Hide all blocks”. That will bypass it and get you to a main menu in first DVD. That is the first step.
So far so good, it’s now starting in the original menu.
At your next section I got completely lost, some explanation of were I’m up against is perhaps a good idea.
Originally, before it was split with DVDFab there were 4 features/titles. VTS 1 & 3 (14:19 & 54:52) were kept complete and went to the first DVD5, VTS 2 & 4 (35.45 & 25:28) also complete went to the second DVD5, also DVDFab kept the VTS numbers as they were. After merging the original VTS numbers 2 & 4 are now found in VTS 8 & 10.
Obviously VTS 1 & 3 will still work in the original menu, but of course not 2 & 4.
What I struggle with is how do I tell DVDRemake to restore the original menu so that it will work again, also noting that that the orginal VTS2 now 8 has a submenu for different sections to play.
Here’s hoping I don’t test your patience too much…