The PM inspected the property, drew up a rental agreement, secured rental insurance, and had any safety issues addressed at the property including the installation of proper smoke detectors.

The property is smoker friendly but the extent of his smoking seems over and above.

Smoke?

A co-signer does not guarantee good behavior, or zero damage, or zero noise, or zero people parking on the lawn or smoking in the house, or bringing in pets or having loud parties, on and on.  

Maybe it is the fact that you have a no smoking policy but they smell of smoke.

Hey everyone I'm a big fan of the forums and podcast and this question may be a little out of the ordinary but here it is.I live in the SF Bay Area and have some very loud, dirty and overall disrespectful neighbors who are renting next door.I had a friend do a title search and found that the home is owned by investors in San Jose (about an hour from here) how should I go about addressing these issues.They regularly party late until about 12am in their small backyard with a stereo outside cranked up, BBQ at 11pm and the smoke fills our master bedroom, my wife is pregnant and can't sleep with all this and it's taking everything in me to not go over there (my wife doesn't want me too).

Technically you can make an excuse like check smoke alarm batteries, replace furnace filter, etc., but a determined tenant could push back on that too and say that they will tend to those things. 

There were two interior violations that have already been fixed-no smoke detectors in vacant unit (because it was being painted), and no handrail on stairs (apparently there had never been one there).The neighbor feels that the downspout in question (with the code violation for needing repair) drains into an underground pipe that is broken (apparently he invited someone onto the property at some point and they used dye packets and his own hose to confirm his suspicion-I tried to called the sewer folks but they didn't feel this is something they would have done), and the water drains through his retaining wall, which he feels is damaging it. 

Holy smokes, 8 dogs?

Admitted to smoking 2 cigarettes a day outside.