yes if you have a exit ticket within 30 days of your entries you'll have no issues. You'll likely not be even asked if you haven't accumulated the days mentioned
it is unlimited but apparently and I can't back this up personally they don't like regular exempt entries. I've had them sit there and calculate my time spent in the country on exempt before being stamped in. I was told this was why. If I hadn't had a exit flight before I'd logged up 90 days I'm sure they would have denied me. It's something to be aware of despite the official rules saying you can fly in unlimited
yes so that's my suggestion. Get a 60 day visa before you come. Could then extend 30 days for a 90 day stay before leaving and you won't have any immigration denial issues