How long have you been marketing the rental? In my experience, most good tenants start looking 4-6 weeks before they are looking to move so they can give proper notice. Once it gets to around the 7th-8th of the month, and the Pay or Quit and eviction notices start going out, the quality of tenants drops considerably. There can still be some good ones but as a %, it drops. A lot. Now at the end of the month, you're going to have a mixture of the good tenants looking 4-6 weeks out and the really terrible tenants that are desperate because they only have a week left either through laziness or nobody will approve them. Right now, May 24, I'm assuming I'm looking to fill July 1 unless I'm lucky with a mid-June move in as, most likely, anybody looking for June 1 won't pass my screening.
I have installed vinyl click flooring on some wavy floors and it has turned out alright. I think you can also find some underlayment that you can glue flooring to. I'm not positive as I had a company install my glue down vinyl 8 years ago but I believe that is what they said they were going to do.