I'm a trombonist!! I'm like a paradox, I'm a non-lazy trombonist, and I spend like all of my time trying to convince the rest of my section to not be lazy... Doesn't work too well though.
And as for slides falling off, it's like impossible for me. I haven't lubricated my marching horn's slide since the 6th grade (I'm in 11th now), and i have a dent in the slide right near the end of it that makes it stop right around 7th position, so I'm all set