Yes, there is a clause included where you can charge a percentage for contract files. This is in the Commissioning Contract as you wouldn't usually do so when working in-house.
Yes, both contracts have clauses that state usage for self-promotion.
If you are living in the UK or the US and want to use this with your international clients you can still do that. These agreements are appropriate for motion designers would wish to have US or UK law govern their client agreements.
A contract protects both parties and should make the terms of your arrangement clear and concise. A client that has concerns about signing a contract should be a red flag.
You only need to sign one agreement with your client, so if are comfortable with the terms in your client’s agreement that would be sufficient. Otherwise, you need to negotiate the terms in one of the agreements. You cannot have two agreements in place at once. If you...