Maxperson
Morkus from Orkus
D&D is a quasi-medieval set up. You're far more likely to encounter a judge who will be like, "Well, the explosion took off your hand which saves us the effort of cutting it off! Ha!" than to encounter a judge with a modern outlook on things.Heck, based on the laws where you live, putting Explosive Runes or a Fire Trap on your book that seriously injures a thief could be against the law, as a judge might rule that the thief had no realistic expectation that touching a random book could cause them harm!
For the rest of your points, I agree. It was a royal pain to create the backup and then even more of a pain to have it close enough to get without having to take 6 months of real time and much more time in game getting back to wherever you kept it. Or else it was on you when the fireball hit and it burned up too.