The owner is now playing games and does not want to pay, since we are almost done. He's paid all the way up until now, so I wanted to find out what our rights would be.
Is the owner your customer - i.e., do you have a contract with the owner? If so, you don't need to serve a notice to owner. If your customer is anyone else - the GC, a subcontractor, etc. - then you are out of luck for lien rights. The 45-day period is a one-and-done. You either serve the notice to owner within the 45-day period or you lose your lien rights, period.