I would just use good common sense when deciding where to stick your amps relative to the drummer. If you can really "feel it" and don't feel comfortable with the proximity, move further away...as long as you can all hear yourselves and it's not a hassle for you or the rest of the band.
I think it's safe to assume that most MI gear (certainly old Sunn stuff) is built to take a reasonable amount of stage and moving/setup abuse. I haven't logged nearly as much stage time as some of the good folks in this forum -- but I've used guitars and amps in close proximity to drummers for about 16 years now and haven't had a failure problem related to drum vibrations (that I'm aware of). I don't play pansy-rock either. A lot of these drummers are LOUD pounders, too. On many stages, you don't have the option of being anywhere except right next to the drummer.
As far as tube stuff goes, my 1st gen. Model T has been going for over 3 years on a set of Svets through countless practices and many performances (some peaking 4 hours continuous/standby use -- bar cover band). I am always right next to the drummer. She still sounds good (though a routine re-tube is coming)!!
Anyway, I think you can do more to protect your head if you're delicate with it in transport...especially when she's cooling down after playing. Also, follow the popular consensus for using your standby switch.