What should be in the written artist terms before anyone says yes?

For CAN-AL, I am treating artist confirmation as something that should only happen after the terms are clear, not just after someone fills in an interest form.

Working checklist so far:

• exact dates and working hours
• wall, board, or live-painting surface
• who owns the surface and who has approved it
• materials and who supplies them
• access, ladders/scaffold/lifts, and weather plan
• fee/support, travel, accommodation, and meals where relevant
• copyright, photography, and credit
• insurance and safety expectations
• cancellation or postponement plan
• what happens if the site or brief changes

What would you want in writing before accepting a first-year public-art or mural festival spot?