Help! SEO for E - Commerce?

[starkj1]

Hi, I'm working on an e-commerce site to that will be selling jewellery and need a little help with how image SEO works. This is specifically in regarding product listings and product pages.

When adding a product with multiple photos, can I use the same alt text for each photo, or is it better to use synonyms?

Does it help to include the product code in the image filename/alt text?

Can the image title be the same as the alt text, or is it not worth including a title?

How much of an impact would optimising all my image file names actually have?

Thanks