Decision factors for switching metal for sculptures

When the metal fabricators for my sculpture suggested switching to aluminum from steel, and from laser-cut to water-cut, I had several questions. I needed to research these things to find the switch acceptable. I’m familiar with molten aluminum from casting sculptures but I've never worked with sheet aluminum. I'm sure more questions will come up as we proceed but here's what I started with:

• Why are the fabricators suggesting a thicker aluminum (1/4 inch) instead of thinner steel (1/8 inch)? In what ways is 1/4 inch aluminum equivalent to 1/8 inch steel?

• What is a comparison of aluminum and steel on durability, strength, and impact resistance?
• Does the fabricator have example photos of their previous cut sheet aluminum at this thickness that I can compare to steel?

• I'm familiar with laser cut metal, but what kind of edge does water cutting aluminum leave? Are there any burrs on the far side? How clean is the cut edge?

• I know cast aluminum has fracturing issues especially when thin. I’d like to know if there are any restrictions on how small an area of aluminum I can put in my design without risking fracturing under normally expected impacts. I’d also like to know if directionality of the shapes is an important factor at all with respect to fracturing.

• Does the fracturing of aluminum change with age and exposure to weather?
• What are the different possible surface finished for sheet aluminum? Smooth, brushed, etc.

• What is the comparable cost of a sheet of aluminum and a sheet of steel?
• Related to cost is it attractive for people to steal aluminum? Will the switch to aluminum make it more likely that someone would steal the sculpture for scrap metal?
• Attachment method: If we switch to aluminum what attachment methods can be used and what can't be used?

• Are there aluminum alloys that are better for outdoor use like there are with steel?

• I want to see and touch a sample of the sheet aluminum in the thickness proposed. I want to take this sample with me. I need that tangible object to help me imagine what the final piece will look like. I'd like to cut a mockup of a portion of my design in the proposed metal.

• How does the aluminum age? What will the surface look like over time? What coating we can put on the aluminum?

• What maintenance is required for the aluminum especially if it is not coated or colored?