My only option is traditional IRA’s and I really want to create a pot of tax free income at retirement to offset the taxable income from my rental income.

i was injured at 16 ( of course I lied about my age to get the job so I wasnt exactly squeaky clean) by a guy smoking pot and drinking on the job. 

First, the whole apartment smelled like pot (illegal in Indiana), then we found some of it in two of the rooms, dog pee stains on the carpet, multiple pieces of furniture left in the rooms, trash everywhere, animals in the freezer, full fridge, mold in the bathroom, chewed up internet cords, and holes in the carpet. 

. #2, your assumption that this will "sweeten the pot" for him is flawed. 10% interest is really not that great of a return for an investor. 

Do I just let them go and be done with it without stirring up the pot?

The drain tile company I hired hacked the knotty pine wood walls in the basement and destroyed the sauna and sauna benches in the basement.

Once you become married, the $$ pot becomes "yours" as a couple, it is no longer his and hers. 

Oh, good timing I am renting a house where one tenant smoked huge amount of pot in one room the walls are black with resin.

So right there we know "timing the market" is a complete mirage, it does not exist, it's what people riding the bench say to make an excuse for why they are not doing anything vs the truth of admitting they don't know what to do, or are letting fear win over work. 

Does being pot-friendly give a landlord a better return, or better tenants, or some other benefit?