I managed in CA, and the owner I worked for had a membership to the local apartment association, but I much preferred the Nolo Press contracts and forms, so I used them instead with the owner's blessing.You might want to see if they have WA contracts/forms.  

I prefer the Nolo Press contracts.  

This is a small incentive to keep them there another year and will be cheaper than a unit turnover,a win-win for both sides.The point is don't let your tenants try to press you for things constantly or control the situation.

Are there alternatives I can press the seller to accept?

I think you are going to be hard pressed to find A/B class properties that cash flow well.  

But sometimes things just happen outside of the landlord's control and this is what it seems like here.I would be hard pressed to pay for a tv when there's no negligence on your part.

I second this Nolo Press tax guide. 

You’ll be hard pressed in a court of law to find a judge in small claims to enforce a tenant paying for a clogged drain, especially if they’ve been good long term tenants.

It's a tough call overall, but one thing we know for certain - the printing press is going to stop at some point, and nonpayments of rents and mortgages are not going to last forever. 

Most laws don't change a lot, so most of it is still on point.I also really love the Nolo Press California landlord rights and responsibility book.