If you have gathered all the forms necessary for your petition then I agree you could fill them out by yourself. If you receive an RFE which is a request for evidence after you file, consulting an immigration attorney will be necessary to help you address the items requested.
When you get to the waiver phase, I agree that you will need to hire an attorney to submit the brief for you.
No, An employee is not bound by an arbitration clause contained in an employee handbook if the clause was not called to the employee’s attention, the employee did not specifically agree to arbitrate or acknowledge the arbitration clause, the handbook states it is not intended to create a contract, employer did not provide the employee with the specific arbitration rules.
Arbitration is a contractual matter and a court will not compel a party to arbitrate if there is not a valid agreement to...
I do concur with my colleagues that additional information is necessary to determine the actions, if any, that could be taken in your situation. I like tortious interference with prospective relationship especially given the malicious motive involved. I would also look at possible defamation if your former employer publishes defamatory statements about your future employer. But it all depends on what your former boss does to "blackmail" your future boss.