What're my chances of staying on Status?

[Mojojojo]

I'm on F1 Visa and on initial 12- month OPT period. My initial OPT ends in Aug'16. I was employed under a consulting firm for 4 months. It was unpaid and I was getting trained. Now I started working in a MNC and may not be able to work loger as the employer is refusing to file for my H1 visa. We know that STEM OPT is in danger and may be cancelled. I've a career plan here. I want to start a technology firm too. Looks like everything is going to be shattered.

1) I want to know my options if I don't get H1 and there's no OPT extension.

2) If there's an OPT extension is approved in court (Americans now might think "Keep dreaming!") , what're the chances that USCIS might say that my employment under a consulting firm is not valid? What documents can I provide them to prove that this($-month under consulting firm) employment period is legit!

3) Most important! How can I start my own business? What challenges will I face in immigration?

I'll be greatful to anyone who can share their suggestions on this. Thanks in advance!