1. Yes, it is one of the eligibility criteria that you have to prove your intent to live outside of Quebec. It may result in refusal if you don't satisfy the officer. May be you can provide your employer's job letter which states that your employer is in Ontario, sign a temporary lease for 6 months, bank statements, driving license, etc. If you cannot provide these documents/proofs within 7 days, you should consult an immigration lawyer or consultant who can provide you best advice.
2. Write the remaining history on the word document. On the top, write your name, UCI#, Form Number, and Page # as well as sign on the bottom. Attach these word document to your original printed and signed form. Then you can upload it. IRCC won't provide you with more slots to upload. You have to combine the documents if the space provided in the form is not sufficient for you.