1. “We are concerned that by providing the manuals to unqualified person [sic] you may be endangering their well-being”.
[…] I have personally never been injured or visibly endangered by working on any kind of computer system, much less a consumer notebook computer. I have also never heard of anybody else being injured by working on one.
They do have a point here though; everyone's seen those laptop batteries on fire. That shouldn't stop someone who knows what he's doing from being able to fix things, but having some incompetent "I'm going to save a couple of bucks and do it myself" DIY:er muck about is probably going to lead to disaster sooner or later.
The repair manual probably doesn't cover disassembling the battery. In fact, it likely says not to do so and warns about a risk of fire. There is probably a similar warning printed on the outside of the battery.
Yes, and someone who knows what he's doing will pay attention to that. Then there's the Darwin award candidate who thinks that those warnings are just Toshiba's way of tricking you to pay a hundred bucks for a new battery when all you have to do is… It's probably also possible to make mistakes in other parts of the computer that will be hard for the battery to handle.
I'm not in favor of hiding service manuals, but I will mention that in the days of CRT's, one could fry oneself fairly easily. (CRT's can continue to carry significant charge at high voltage, for varying periods of time after being turned off.)
P.S. As a specific example, combine this with the original all-in-one-box Macs' shitty power supplies (and co-located video tuning controls, now that I think of it), and you had a not too uncommon reason for people to go poking around the CRT.