Yes you can. We were just there 2 weeks ago and that's what we did. Enjoy your experience!
Yes I recommend purchasing online if you are going on a weekend or in the afternoons, we were there on a Monday morning and would have been about 3rd in line when we got there but a line had formed to get in by the time we left so online is faster but they can be bought there
Either way
Yes
You can also buy them online and a ticket with bar code will be sent to your email. Much easier than the line. I was there 3 weeks ago and the line for tickets was crazy.
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