I would prune off the side shoots now, and concentrate on training a good trunk. If you want to leave one or two shoots temporarily to sample a little fruit, just pinch the tips after they get a foot or two long, to prevent them from growing too much. You want the energy to go into growing the trunk, but muscadines are so vigorous, a couple of clusters will not make much difference.

You've chosen one of the most common and successful forms of asexual propagation called layering. It occurs in nature and is soooo easy to copy according to our own terms. Come spring, you should be able to sever the new plantlet from the mother plant. Yes, it will be a fruit producing vine. Don't be tempted to pull up your runner to check on progress. As a matter of fact, you should secure it in some fashion so that it doesn't come 'undone'. Also, your buckets of rich, black soil need to be watched so that they don't become waterlogged and soggy. Even the best garden soil can turn into something 'different' when put into the confines of a container. Hopefully, you put drainage holes in the buckets.

To me it's confusing when someone says they pick at breaker stage b/c four breaker stages are recognized in the tomato industry. Breaker 1 is where there's just a blush at the bottom. Breaker stage 2 is color maybe up about 1/3 of the fruit. Breaker stage 3 is color up to about half. Breaker stage 4 is color almost up to the stem. I don't pick mine until there's color at least halfway up, but I guess there are folks who have critter and bird problems who might want to pick them earlier. And most of the time I let them ripen on the vine b'c I want to. LOL It all depends on what your usage for the fruits is, how many plants/fruits you're growing and knowing what kind of shelf life they have. And yes, shipped in fruits are picked usually at breaker 1 and then put in large chambers and gassed with ethylene gas to speed ripening. Tomatoes normally produce ethylene gas themselves as part of the ripening process, but gassing them externally does speed up the process. And folks do the same thing when they try to ripen fruits in paper bags or wrap them in newspaper. It's not that those shipped in ones that look anemic are unripe, rather, specific commercial varieties have been developed that are more amenable to gassing and the taste was never there in the first place. Sigh. Carolyn

2nd photo is aphids - I've observed lots of them on new growth of my grapevines as well. You can wash them off w/ a sharp spray from a hose. I leave them alone & let the ladybugs take care of them - they never seemed to affect the flowers or fruit & vines eventually outgrew them. 1st may be a female cottony cushion scale insect - I just rub them off the plants w/ gloved fingers. Both are sucking insects