I've over-forked a fork. a Fox 34 @160 feels pretty noodly, but acceptably 'compliant' @150.
Also running longer than recommended forks on all my bikes for years with great success. Personal favourite is my 2002 Turner XCE with Marzocchi Z1 Drop-offs @130mm and a fox vanilla rear shock. I hate to admit the lazy seat angle has me walking up some of the steeper climbs, but the thing is magical when up to speed.