IME, people use the day bed for siestas, & late night shmoozing.
It may well be that there were more than the official number of pax in there. (other friends turning up etc)
Also the pool pump very likely did turn off in the evening, so it may be they didn't understand, (at night if you swim with no pump the skimmer flaps tap quite loudly.)
Leaving the bins inside was lazy (& smelly) & causes ants/wasps to enter.
If they broke tiles around the pool, there must be some really dodgy tiling. I have rented a villa for 15 years & no one has ever broken a tile.
Never put white cushions on a holiday let, even just sitting with wet cozzies can stain. its one of those items you know you will change annually anyway.
But, the place was clearly not cared for, do not return their caution, & replace with a different type of sofa.... (most people would have tried to hide the damage to the day bed, so clearly they didn't care)
Make sure you have a damages deposit that covers the damages.
People moan, but if they don't trash the place they get it back...
Also put a clause in your contract that if the property is not left in an appropriate manner there will be 100€ deducted for supplementary cleaning
It goes with the rental business, unfortunately there are a lot of people who simply do not know how to behave. (the British are not the worst :O) )