Arrival at 11:10. As far as I know application closes at 12:00. So Cutting it mighty fine if anything went wrong or any delays. I would not be recommending people to rely on your strategy.
It is 'supposed ' to be the owner of the property of the Landlord. However if they decide to fine you as the tennant then there is not much you can do about it. If the condo or house where you live has an office or the Landlord has a registered business they can submit the TM30 online for you. If not then the duty really falls on you as the alien to make sure you are registered. If the Owner of the property is out of the country then just go and register yourself to avoid a fine.
Yes no limit (air), but always remember it is ALWAYS up to the Immigration official. So if they decide that you have 'Too many' in their eyes, they may give you a warning. Always carry 20k baht in cash to support your stay, should they ask (as this is a requirement whether they ask or not). I would also recommend choosing male IO's at the airport and not female as they like to make a scene a lot more than the men. (again not sexist, factual).
You have a visa exemption, not a tourist visa (this is 60 days). Also you are not doing visa runs, you are doing border runs by land or leaving and entering by air.....There is no limit by air....only by land......why not go and get a visa from Laos or another consulate....? and extend for 30.....= 90 day stay.......There are various agencies that can take you there.....or get a cheap flight to Udon and cross the border by bus.....
You have a multiple entry visa. You can enter for 60, extend for 30, then leave and come back for 60 and extend that for 30 again. If you re-enter before the 'use by date', you can get more time from your visa.