Advice Required: Tetras Fighting; String Algae; Shrimp Hiding?

I have some black neon tetras, a shoal of 10, and although I've not had them long things have been quite peaceful. I'm wondering if it's possible that you have more males in your group, and they could be fighting for females. I'm only guessing though. I don't know if increasing the shoal size will help, and I'm sure that the more experienced keepers will be able to offer some advice.
Algae problems can happen when something is out of balance, possibly too much light, or possibly not enough plants to out-compete the algae for the nutrients. Manual removal of the algae is a good idea. You may want to consider reducing the light, and doing some water changes to remove any excess nutrients. Do you have a lot of plants in the tank? Do you use fertilisers? Is there any excess food in the tank?
As for the shrimp, it is normal for them to hide. Give them some time to settle in, they might be really busy hidden away somewhere stuffing themselves silly on your algae.