For your first query:
You should not apply for Google Adsense account until you have good enough self written contribution. I recommend you to contribute much to RS then apply.
Generally it is recommended to apply once you reach diamond level in RS, meanwhile you can enjoy earning from RS. We will pay you for your self written contents.
It is up to you, the more you contribute the more you will get.
Note:We accept only self written contribution, if you not abide by, it will lead to rejection of your resource.
Hope to see good contribution from you.
Thanks and Regards,