I retrobrighted plenty of things and also damaged some too until I learned. The trick is to NEVER RUSH. Be patient, don't let your retrobright solution dry, if you're using h2o2 never go over 15%. Also if you're using oxy be very careful -TAED is responsible for most of the cases when blooming occurs.
True that. Especially with keyboard lettering. Be very careful. I know a lot say it's safe, but there are some keyboards that hydrogen peroxide would ruin their lettering.
I've used normal hair coloring creme peroxide, 9%-15%. Best results with the 15% and plenty of UV/sunshine. Two to three applications (each lasting about 1.5 hours in the sun), followed by a good soapy wash.
TIP: Once applied, wrap it up in cling film to prevent it from drying out.
The Amiga 1000, even the keyboard, is really resistant to damage - I've retorbrited mine and it looks amazing (not that it was that yellow to begin with, but had some patches).
The Amiga 3000's front bezel as well holds up pretty well, the logo etc will not get wiped off. The keyboard, though, be careful with the key lettering.
Oh, also, for goodness sake make sure you wear gloves at ALL TIMES! You may not feel it during the application, but come a few hours later you could be seeing strange little white dead skin patches and irritation on your hands which will probably need cortisone to cure.