1. To freeze the wrapped (but not fried) spring rolls, place them on a baking sheet (single layer with a gap between each roll) and put them in the freezer. If you want to stack them, place parchment paper or paper towel on top of each layer. Once frozen, you can transfer them into Ziploc bags. To fry from frozen, do not thaw first. Just fry directly from frozen. Add an additional 1-2 minutes when frying from frozen.
2. If you want to bake these, you could. It will still be crispy but the color will be paler. Preheat the oven to 425 F, brush the spring rolls with oil and place them seam side down on a baking sheet lined with parchment paper. Bake for 15 - 20 minutes. At this point, they should be done but if you want it a more golden brown, bake another 10 minutes. If baking from frozen, they'd take about 25-30 minutes in total (instead of 15-20 minutes).
3. Bean thread noodles (aka glass noodles or cellophane noodles) can be found in most Asian markets. They are not to be confused with rice vermicelli noodles which are made from rice and are white in color when cooked (as opposed to transparent for bean thread noodles). Some packages may be labeled vermicelli but as long as they aren't made of rice, they're bean thread noodles. They come in various thickness. It's up to your which ones you like.