Firstly where the heck have you been to surf 6 ft waves



Secondly no, you can carve a big board you've just got to make sure you get that back foot over the fin or centre fin. Also use the paddle and stroke the board round in an arc (swiftly). After a couple of goes you'll get the feel of your particular model of board. Like everything else just practice.
Thirdly you'll probably end up with a quiver of boards like the rest of us...start out being adamant you're just after the one utility board for the family and end up with an addiction to Stand Up Heh heh.