Your questions are why it is good to book with someone who knows the destination really well. You do not pay one dime more and often, we have savings you could not get on your own. The first simple question to ask who you're booking with is: Have you ever dived Galapagos? And ps, we love talking about diving the Galapagos.
Sorry, but I always hear stories from liveaboard operations about people not having the right info, etc. It can turn into complaints they have to deal with and they don't like that. It is a remote destination so it helps to deal with someone who knows the destination. It is only an advantage for you with zero disadvantage.
A number of people have lots of experience offering dive travel to Galapagos. We happen to be the only one who doesn't offer any other destination than Galapagos. It's a niche, but we know our little corner pretty well.