Andrew,
Capsizing the 4.9 is not a big deal. It doesn't happen nearly as fast as on a dinghy--my C 15 (fifteen foot single trap two-person dinghy) capsizes very fast by comparison. When the 4.9 goes over, you feel it coming and just hop off and get set to right it. Keep in mind that the 4.9 is not as wide as the I20, F18, or Tornado. So the capsizes are as bad. Best to find a nice sandy beach to practice righting the boat--tip it over then right it a couple time to get a feel for it. Then you'll be ready on the water. I'd be happy to go out and demonstrate a capsize for you on my boat. I'm pretty good at it ;-)

Also, you might want to sail the boat a few times with main only or with jib and main only for simplicity.