Consider a wire that overheats for whatever reason- poor connection, etc. Will it start a fire in the wall? Please take all the safety precautions. It's not worth skimping on cost on this one. Even if you have to redo the job, It's matter of life and death. We know about fire in Chicago!
Also I wonder about your liability if something happens for work not done to code. We are all assuming some code violations here based on some of what you described.
