The fingerprinting and photographing is for EVERY entry. Sometimes when the queue is busy, the officer will just waive you past or will wave every third or so person past with only a passport check. But if you're an American, you get in line, then about halfway through you are shunted over to a different line, get fingerprinted, then kind of get back in line and get called over to the next passport officer. It's a real pain in the butt and seems clearly designed to make it a pain in the butt. But hey - it's their country and I won't complain about it. But yes - if you're an American, you go through this EVERY time you enter. Period.

As for passport expiration, most countries on the planet will require that your passport have at least six months left before it expires for you to enter the country. Places that require you to get a visa beforehand will deny your visa if you don't have at least X months validity remaining (usually 6 months). Other countries that give you a visa stamp upon entry (lots of people don't realize that you get a visa everywhere - that's what the stamp in your passport is, unless you have a pre-arranged one) will usually also require this, and if you don't have 6 months left, they may make you turn around and go back home. If you are going to be close with your passport expiry, then go ahead and renew it now.