Triggering or destroying explosive runes

[Avadriel]

Explosive runes is one of several spells that can be disarmed by a rogue or other character with trap finding. No one argues with that as far as I know, but it leaves me with a couple questions.

1) If someone without trapfinding attempts to disable an explosive rune, does it automatically go off, or does it only go off if they fail the check by 5 or more while just not getting disarmed on a success?

2) If someone tries to disable it by some other means, such as scribbling or painting over it, what happens?

3) if the explosive runes are on a book, and that book is set on fire, does anything happen?

4) a book has an instance of explosive runes on each of its 100 pages, someone picks up the book and starts reading the first page, does one explosive rune go off, destroying the book without setting off any of the other explosive runes?

http://www.d20pfsrd.com/magic/all-spells/e/explosive-runes

[Ipslore the Red]

1) It goes off.

2) It goes off.

3) The book burns. The explosive runes are destroyed without being activated unless someone manages to save the book.

4) Yes.

[Nothing]

4) Yes, unless the book can survive the 6d6 force damage (such as one with the Hardening spell cast on it).

The only sure ways (I know of) to deal with the explosive rune is to have a high enough disable device skill and trapfinding, reading it in an antimagic field, or nuking it from space (wish, miracle, disjunction).

[CommandoDude]

Is it possible to make a Scroll of Explosive Runes that can be cast later from said Scroll?