lavaan: how to analyse residuals of a latent variable

Can I include criminality among those and thereby get the common part
of criminality and fire.setting "out of the way"?

No. You already regress fire.setting on criminality since it is an 
indicator in the measurement model of criminality. In other words, the 
'criminality' part is already regressed out.

Yves Rosseel
http://lavaan.org