My last tenant was a smoker unbeknownst to me, and a lot of the smell dissipated when I cleaned a large sliding glass door with a mirror finish.

I would definitely pass on smokers if possible.

And if you're having trouble leasing the unit, I would probably drop the restriction on being a non-smoker and just say they can't smoke in the unit (although they likely will). 

, and if you want to live in it eventually you probably dont want smokers. $5k for the back deck??

We don't rent to smokers.

Previous owner was a heavy smoker and left behind all furniture and personal staff(that was part of the deal).

If a tenant prepaid a year in advance and the PM passed along all the rent to you at the beginning, they'd have to bill & collect money from YOU to do necessary repairs to the unit during the year, they are not going to do that.As for the weed issue, most people I know smoke weed in some capacity these days, and I'd much rather have a weed smoker in my units than a cigarette smoker.

I will require parent co-signers, but I think I will do other basic things - "have you been evicted, how many people will be living in the house, are there any smokers, provide references" , etc.

This apartment was occupied by smokers for 16 years.

We pulled those out (all the previous tenants were indoor cigarette smokers so all drywall had to be removed from the entire property).