Adjustment of Status - I-485

Hi folks,

I am an F1(husband) student married to a US citizen. I filled I-485 on June 22, 2016. I received RFE on August 2 related to I-864. My joint sponsor earns $100k with a family size of 6 (including me). RFE was stated as follows.

1. The joint sponsor lists their current income on Form I-864 as an amount to be considered as sufficient; however, no evidence has been submitted as proof of current income. Submit the following evidences:
          a. Pay stubs or other documents of pay for the previous six months
          a. Letter of employment containing date of employment, salary, etc
2. Based on the documents submitted with form I-864, the joint sponsor income didn't meet 125% of the poverty guideline.

My question for no.1a, my joint sponsor joined school for fall 2016. He will work as a part time so I can not submit a letter of employment. Is it okay to submit pays stabs only? Second, the RFE no.2 is weird, the 2016 125 % poverty guideline for 6 family size is $32,580, which is much less than my joint sponsor income. Does any body have similar experience, I need help on these two issues.

Thanks for your help!