Would these be good for 3A? GITD is cool and i want to know if they are good for 3A 
also do u need to like place the yo-yos next to a light or something so it glows in the dark when the yoyos glow get dim?
Any modern yoyo will be fine for learning 3a with. Yes, to recharge the glow, you hold the yoyo up to light.
glownasties aren’t great for 3a. They have a high walled organic/h-ish kind of shape, and aren’t the most stable throws. You’re better off getting 2 psgs, magic yos, etc. something more stable with a low wall.
And yes, they work the same as any other glow in the dark things, they need light to charge them beforehand.
While the DieNasty is good, the Starlight would be better, mostly from the perspective of the shape of it. However, the DieNasty I feel is a touch too narrow, but has better weight than the Starlight, and I think it’s more stable.
If you gotta glow, I’d really suggest the Magic YoYo Sprite D5:
http://http://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-ash4/1005295_345761415553971_87122938_n.jpg
More of a 1A throw, but with the different colored weight rings, it lends itself to 3A quite well if you need to mix up the colors.