There are loads of free legal aid clinics that provide guidance on landlord tenant issues. I would definitely give one of them a call to get a better idea of where things stand under WA law.
I do not know WA landlord tenant law, but state codes are easy to find on the internet and to look up. You can also read up and get a better idea of the law.
There are some differences from jurisdiction to jurisdiction on lockout rights. Some jurisdictions consider a lockout an eviction and require a forceable detainer action (court eviction proceeding) before a landlord can lockout a tenant. Other jurisdictions do not consider a lockout an eviction, but only allow a landlord to lockout a tenant under specific circumstances. Check WA law to see where they come down on this.
Also, generally speaking, a landlord can sue a tenant for damage to the leasehold. Most jurisdictions have very specific requirements that a landlord must take before deducting damages from a security deposit. Without a security deposit, a landlord would have to go to court and prove up a claim for damage to the leasehold in order to get a judgment against a tenant. Most courts would require the landlord to document the damage and cost of repairs.
Finally, when there is no written lease agreement, most jurisdictions presume a month to month tenancy, meaning you still have rights as a tenant. Check WA law on this as well as there are differences in jurisdictions on termination of a month to month tenancy.
My experience with jerky landlords is that they know that they are not following the law and are reticent to show up in court to sue tenants for damage to the leasehold. But some people are just dumb coming and going. So, best thing to do is consult with a legal aid clinic so you have some piece of mind going forward.