The seller has usually one chance and you might ruin that for them.

Not allowing pets is the best option not to ruin the floors. 

Tire plugs in my area are $20 each, no sense in ruining a relationship over a small amount of money.

It has exceeded it's useful life and it is so much easier to replace it now, rather than waiting until it has leaked and ruined a tenant's clothes (water heater is in a closet).  

Everythig is going smoothly and I have their security deposit but I just wanted to ask if I can negotiate with them to see if we can meet somewhere in the middle because I have no proof of them ruining things. 

I start advertising 30 days before the unit is ready and generally have a tenant ready to move in after renovations are complete.As for online reviews, it's common for a good Property Manager to get bad ones from tenants they've kicked out.Go to www.narpm.org and search their directory in the upper-right corner of the page.If you make a mistake and hire a bad Property Manager, it can ruin you for life.

I usually try and set up the team before I start looking, so you can hit the ground ruining when a deal comes along.

This is ruining that!

My rule of thumb is tenants will ruin anything they touch even when they have good intent.

They're only your best tenants if they are not doing things to actively ruin the property such as building an avenue for termites into the house.