i-DVD 4 small questions - advice needed

Firstly a happy new year to all, it has started stressfully for me - I hope I have made my last movie in i-movie and can this year graduate to FCP.

Anyway here's the deal, I have just burned my first paid project (in i-DVD)which is a very detailed hour and a half long i-movie.

I encoded it on professional setting, the third one down - so I could fit it all on, but unfortunately there was no room for a highlights trailer and photo slideshow I wanted as bonus features.

The DVD's I am using are plain white blanks from a computer mall and I have already bought 30 of them.

My first question is:

Is there a way I can squeeze everything onto one disc without having to hunt down special double layer discs which may not have the option of a plain white printable surface or will I be better off presenting my product as a 2 disc edition?

My second question is:

The Menu page doesnt come on when the disc is inserted into a standard DVD player, the movie starts automatically, however it can be found by pressing menu on the remote but ideally it should go to the menu page first. Did I miss something?

My third question is:

The disc was burned after about 13hrs. Having pressed 'Done' and saved the i-DVD project, to burn another disc do I simply re-open the project and press burn - will it take the same length of time as the first to burn and canb I make alterations to the text in the menu without having to start from scratch?

My last question is:

If I need say 10-20 copies and want the best quality, should I burn them all on i-DVD or will I get just as good quality making copies in Toast Titanium or Burn from the master? Could a shop do a large batch that will be of the same quality?

Many thanks.