So now I’m going through the inspection time and I kinda got screwed on their counteroffer cause they accepted my price (299,000 on a 5br/2bth 3000sqft In Portland, OR) but they wanted to cut my inspection time in half from 10 to 5 days.

If/when the inspectors find problems you will need to decide if you want to try to get the seller to fix them, give you a credit or accept as is.  

That said, you can always go out and hire a lawyer to transact the property if you've already identified one and have an offer accepted. 

Weekly stays beyond 28 days and you now have yourself a regular tenant.Same applies if you initially agree to anything more than 28 days, like accepting payment for and agreeing to let them stay a month.

If you don't give the seller a chance to accept your better (for you) offer, he will never say yes to your better deal. 

@Lee Ripma is correct - as a California resident actively engaging and managing an LLC from California, California will declare nexus and require a registration, a tax filing and a minimum $800 fee each year.Marketing into other states may or may not create nexus (depending on each state's laws, so look them up) and need to register/file in that state, but as @Wayne Brooks indicated, you will most certainly need to be registered in any state where you want to sign contracts and otherwise conduct business in that state.From each state's point of view, anybody who wishes to sue you must be able to do so in the state where the transaction took place so you must be registered in that state with an agent who can accept legal service on your entity, should the need arise. 

PS: I would check into whether there is any kind of law in your state requiring them to accept a notary.

On residential sales I see flood zones as a major concern, but on a rental property many investors I've talked to see this as an acceptable risk as normally the insurance would cover it the cost of any repairs.

We had our popcorn ceilings tested before removal and that was negative. 

Update :Received the test result of 3 samples the asbestor inspector send for inspections and the result came back that there is no presence of asbestos.