most people don't actually do enough takeovers, ( as compared to you, apparently) to actually put it on a score card. I'd guess that most just look at the quality of the work. Look at the placement and quality of detectors, and contacts to see if they look amature-ish or installed by inexperiened installers, splicing and connection methods) Do detalied questioning about the problems the client has experiened ..... If there are any potential problem spots, do a physical inspection and metering test to confirm any major problem, ( Like funky resistance readings) And determine if you can get past the lockout codes.
Once getting past all that, if .... (and letting the client know up front), if during the take over, other problems become apparent, bring them to the attention of the owner and they've got to be fixed at whatever the cost. If not, THEN unfortunately, you have to walk away. That's the way I do it.
I wouldnt take the time to set up any kind of "three strikes you're out" system, because most of my jobs are new large residential, new construction or for existing clients with only an occasional take over.