Overall you give good advice, the only thing I would add is that DCA is also good for people who don't have a big income and therefore can only invest what they save from their paycheck. For most salaried people. I am not a newbie and I do it.
Some investors may speculate and some can think that the price of bitcoin may still decrease, they can because if that not invest at once but start to DCA in a way that if their analyses or speculation is favoured, they will be able to buy more at a lower prices. Some investors will even buy more when the price of bitcoin becomes lower and some investors will invest all at once after many weeks if DCA when the price get to a lower targeted price.