Does a clamping current specification under Absolute Maximum Ratings imply that less current is OK?
Absolute maximum specs are only to not damage the chip.  They do not guarantee correct operation.  I would not try to extrapolate from absolute maximum to normal operating.

My advice is to add a small Schottky diode for each relay.  You need very little voltage and current capability, so a phyisically small diode should do it.

Clamping current is a area where it is a especially bad idea to be a test pilot.  There are various topologies for dealing with clamping current, and some have more significant effect on normal operation than others.  For example, old PICs like the 16F877 had a rather liberal clamping current spec and you could get away with a lot.  Newer PICs have tightened down on the normal operating spec to the point where it's clear they don't want the clamps to ever come on during normal operation.  This is not a place you want to guess what you can get away with.