I leave some on a second year vine if it's big enough. So vine size is the key in my opinion. As with all young fruit vines/trees, I thin extra heavily. So how big is your vine? What is the caliper of the trunk? How big and long are the canes and how many did you leave? How many sq ft would you expect the vine to cover this year? Is it in full sun? These are the factors I'd consider.

I don't like Cherry tomatoes. (Ducks as rotten tomatoes come flying at me LOL). I like grape tomatoes because they are sweet, but still have the tomatoey flavor I'm looking for. I've never met a cherry I liked. I think I also don't like the shape of cherrys for my salad. But I hear very good things about Black Cherry, so I'm going to try that this year. Still, I want a grape tomato as I like them for my salads. The 3 I mentioned are what I already have seed for. I don't think I want to go to the trouble and expense of paying $5(with shipping) just to get seeds for a grape tomato.I checked the exchanges section and unfortunately no one was offering any fabulous grape tomato seeds, so these are my options. By the way, has anyone ever tried sweet pea curant? It sounds so flavorful.... and cute too.

It sounds like erineum mites. If so, only esthetic. But they won't go away if you ignore them. They're very tiny mites which over-winter underneath the bud scales

Where are you located? Grape vines here live for many decades and never die back to the ground! But they do need consistent pruning each late winter or early spring. A 3 year old vine is not a particularly "young" plant and should be ready to bear now. Your grape was likely already at least a year old when you purchased and planted it maybe even older. The first year in the ground you need to remove flower/fruit to allow proper establishment and the development of the root system. And the second year, it may or may not produce any flowers or fruit anyway. By year three (at least a 4 y.o. vine) you can let it fruit but do not let it produce heavily. Thin out the clusters so that each has 12-18 leaves supporting it or roughly each cluster about 18-24" apart.