You were just starting to see the benefits of dinghy sailing. A dinghy can make you one hell of a sailor.
One person should be enough ballast. I have a boat with 132 sq ft of sail. It uses an 80 lb centerboard for ballast.
Gybes happen real fast but are very do-able single handed. You have to be ready for it. Gybing a dinghy is different than gybing a cruiser.
I let out the sail a little bit so that it's not as powerful, start the turn, grab the sheet and yank the main over as I transfer to the other side and hike out when she powers up. The sail fills, you steer to keep it on course, and you blast off with a huge smile on your face. Don't worry about the jib until the main is over.
It's all timing that comes with practice. I spent days just practicing gybes.
From my experience, executing a perfect gybe on a dinghy is much more rewarding than on a cruiser (I have both).
I rarely sail with a cleated main. If you go over and your main is cleated, then it becomes very hard to right the boat. There are ways to get leverage so your hands don't get so tired. If winds are very light, I'll cleat. If it's 10 kts or more, I hang on to the main. I always have a hand on the main no matter what boat I'm sailing, even on my cruiser (I cleat the main on my cruiser but things happen slow enough that I can uncleat it quickly enough).
Also, when she tosses you in the drink, get to her centerboard before she turtles (I'm assuming she did since you had mud in the mast). Once she's turtled, you've got your work cut out for you. Just use steady pressure on the centerboard and, if the main isn't acting like a huge fin (which it won't if it's not cleated), then she'll come up. Brute force isn't going to work. If she's turtled, start with applying pressure to the edge of the hull. I'll reach for the centerboard and pull it until I can get my foot on the edge of the hull. I'll put my weight on my foot and just hang on to the centerboard until she's on her side. Then just pull on the centerboard until she's back up.
Take the boat out with just the hull and centerboard and practice righting it. Anyone sailing a dinghy needs to know how to right it for safety just like anyone sailing a cruiser needs to know man overboard drills.
You can get seacocks for dinghys that you can open while underway. Moving will pull the water out, then cap it when she's drained and continue on about your day (think Sunfish).
Pushing a your limits in a dinghy is a relatively safe way to increase your skills. You're not really introduced to dinghy sailing until she tosses you into the drink.