Not true at all , do you realize how many kick boxers are top rated boxers and and there have been two that I think held titles simultaneously and I do not think either one of them could beat A top rated MMA fighter.
Not at all true I know It is more likely the other way around you have no knowledge for grappling skills
Who? Which top kickboxer would be able to last in the boxing ring? Badr Hari was a good, but once he planned to switch to pro boxing the first sparring session made him cancel these plans.
Get to grappling first. Most of the guys who woul try to grapple would be knocked out before it happen. A boxer doesn't go unprepared to the octagon. It's easier to learn how to resist a takedown, than to learn how to box well. Most MMA fighters are terrible with their fists.