I think they only give you 90 day non-O in the beginning. You can renew it every year afterwards. They really don't want to give a long term visa unless you make some contribution. My wife is Thai, but staying in Thailand has never been convenient.
Marriage visa has gotten more strict now. Proof of income is hard to get recognized. I was denied a renewal when I showed them the contract and the deposit record. You have to have a deposit for some time in most immigration offices. They even check again a month after the renewal application. They are more flexible with retirement visa. There's a plenty of agents who can help you.
Most hotels will do. Most landlords will never do it. You may want to do it yourself online. I had to pay a fine for my landlord when I went to do a 90 day report. This is probably a part of the institutionalized extortion scheme against expats. Don't stay too long.
Don't marry bcz of the visa. Find other ways and wait until you know enough about Thailand. There are lots of things to know before you make a big commitment.