Tier 1 ext for self employed & confusion in immigration

Hi all,

I have 2 questions:

1. What proof does a self employed work from home person need to give as income/employment proof at time of Tier 1 extention?

2. It says in the immigration rules that for ILR, a Tier 1 needs to show he/she is economically active. Does this mean he/she needs to be economically active for all 5 years before ILR? What if I decide to stop working for 2 years in the middle to take care of kids, and resume 6 months before ILR application?

Hoping someone can help!