Two years ago, the homeowner offered a friend a place/room to stay when she was transitioning from one place to finding another. The friend has become an unwelcomed guest. There has never been a written agreement, and friend contributed to costs in the beginning until she lost her job soon after. Homeowner has accumulated expenses on behalf of the friend with friend promising to pay when she finds work. When she has found temp job, it was barely enough to cover gas, insurance, and food for herself. Friend has been living free for over a year. Arguments without resolution have been about contributing in some other way, reducing long distance calls, and just cleaning up after self.

The homeowner reached breaking point one night and called the cops. They suggested starting the eviction process and notice has been served. The friend is now taking the toilet paper holder and hand towel holder off the wall saying that she paid for them and is supposed to remove anything of value from the house [regardless that the friend promised to pay $1000 for dog's medical costs 6 months ago.] Friend said she is going to move out slowly so boxes are stacked in most shared corners of the house. Does friend have right to shared items that she happened to purchase (i.e. bath towels) when she owes so much?

Yesterday, homeowner moved a bunch of her boxes from the living room to another room and friend said that she talked to lawyer and that homeowner can't touch/move any of her belongings unless homeowner called friend first. Homeowner asked friend to clean out one of two shared bathroom drawers so it could be used for guest items; she refused giving her cabinet space.

Friend has also given a key to another friend who has stayed at the house when friend wasn't there. Friend assumes rights of tenant without courtesy of roommate/friend/guest.

Homeowner currently has summer guest staying in the spare room with written agreement on length of stay and responsibilities - i.e pay half for electricity, clean up after shelf, ask to ???. Guest feels grateful for place to stay, but doesn't want to pick up the costs of the non-contributing friend or put up with the inconveniences (boxes in hallway that supposedly can't be moved).

What are the rights of the homeowner when friend (roommate) during eviction waiting time? On the 30th day, can anything left by friend be removed/stored in the garage or sold? What about having friend invite other friends to stay while they are gone?

The firend having a friend there is too much and definitely not part of the arrangement, so you should have told them to get lost or call the police. If this is a guest, then I am wondering how they got rights as a tenant. I think you need to consult a local attorney. There is not lease and you say the word "guest" not tenant meaning that you can unguest a person when you want them to leave. I would stop being intimidated by the guest and their attorney since there is no lease, no oral lease and no tenancy, but just you being taken advantage of. I think you need to stop being intimidated, find a public storage facility to put the guests' items until they claim them and have to pay to claim them, but ensure nothing is lost or taken and get your own attorney.
If they sue you, then you can say you relied on counsel's advice and that this was a guest, not a tenant, so there were no rights of a tenant.
Good luck and stop being nice and being taken advantage of.