I want to totally close off my existing flue and
capture 100% of the heat just as if it were a vent-less model. *The only
difference I can see between the two models is that the ventless models are
required to come with a special oxygen depletion sensor (ODS) as part of the
pilot flame apparatus. *I was going to replace my gas logs but instead I
have cleaned my stove, blocked the flue, removed the glass front door, have
run the stove, smell no gas fumes, and constantly monitor the CO with a
detector which reads zero. *Anything wrong with this setup?

CO (carbon monoxide) is produced where there is not enough air for complete combustion. Where there *is* enough air for complete combustion (which seems to be the case with your gas stove), CO2 (carbon dioxide) is produced instead, which your CO monitor might not be sensing.
The danger in this situation is that CO2 could displace enough normal air that you just might not wake up some morning. Your house might be drafty enough that in the *short term* you might never get a dangerous build-up of CO2. But really, I would hate to think that someone turned into a vegetable when I could have warned him.
At an RV place you could probably get a thru-the-wall venting type of a heater that would keep one room more comfortable if that's what you want. A High Efficiency gas furnace (over 90%) that is meant for a whole house still has a vent, even though its a 2" plastic one. It operates in a fairly air-tight room of its own, with a combustion air inlet and a fan-boosted outlet to get rid of the carbon dioxide and water vapor.