Could you elaborate on what you mean by “yield” and “transaction fee insurance” for someone who is skeptical but open minded to home mining?

I think when you say “yield”, you are referring to either newly issued bitcoin and/or transaction fees earned by a mined block. I also suspect “transaction fee insurance” may either refer to lowering the effective transaction fees one pays over their lifetime due to block rewards offsetting the costs, or just the fact that when you successfully mine a block that contains your transactions you effectively pay no transaction fees.

I think you are arguing that if a home miner makes use of energy sources that are already expended in their living space such as heaters then you can effectively get free bitcoin lotto tickets (ie chance to win block rewards). My concern is that to use such energy sources in a way that does not increase energy demands (significantly or at all) then the probability of successfully mining blocks will be too small to matter of a long period of time. 

I want to be wrong, so I would love to hear your thoughts to why this is not the case.