I've had to loosen and re-tighten the rack mounts a couple of times to replaced/re-route the rear light wires, so that probably counts and maintenance. I also had to re-tighten them after the bolts at the seat stay mounts were stolen at Beamish last autumn.
Is there something like grease but which isn't greasy which workshops approve of stuffing into the heads of bolts which would keep undesirables out yet be realtively easy to schloop out when the bolt needed to be adjusted? BoltWax™ or something? The bolts in the unused bottle cage bosses underneath the downtube and the bolts in the unused front rack mount points would also benefit from such a substance.