However, if they are complaining a couple of months into the lease and they knew about the smell before the decided to move in and you didn't mention anything about removing the smell prior to the move in date, I would tell them to light a candle.  

One issue seems more serious -  the lights keeps flickering.

Can anyone shed some light on this topic?

The buyer typically gets no warning that a first lien exists on the home.The buyer gives the seller (or the person in charge of the sale) a down payment, moves in and begins making monthly payments to the seller.Source: Texas RioGrande Legal Aid

I have dark walnut porcelain tile floors, expresso cabinets, pendant lights, light granite counters, white walls.

This can be send here off Woodward now with a light rail that has broken ground seen here>>>>http://detroit.curbed.com/2016/3/22/11284676/sneak-peek-construction-development-scott-at-brush-park

I warned the tenants at that time to not throw paper products in the sewer that can cause back-ups.

Here is an example of ours:LAUNDRY ROOM RULESUse the laundry room only during the hours of 8:00 am to 10:00 pm; Start loads no later than 8:30 pm as it takes about an hour and a half to complete washing/drying; The washing machine cycle runs for 25 minutes and the dryer cycle runs up to 60 minutes.Remove clothing promptly from machines; plan accordingly.Open/close outside door quietly; gently pull the door closed and use your key to lock it.Open/close appliance lids and doors quietly;Do not overload the machines; overloading of the washer reduces effectiveness of cleaning and overloading of the dryer poses a fire hazard.Clean lint filter before and after running a load in the dryer; Keep the area tidy.Turn off lights and lock door when leaving.If you experience any problems in using the laundry room or equipment, please call the owner/manager at XXX-XXX-XXXX.THANK YOU FOR YOUR COOPERATION!

Similarly, a policy or practice that does not consider the amount of time that has passed since the criminal conduct occurred is unlikely to satisfy this standard, especially in light of criminological research showing that, over time, the likelihood that a person with a prior criminal record will engage in additional criminal conduct decreases until it approximates the likelihood that a person with no criminal history will commit an offense.  

tread lightly