2) a) What exactly do you need from that page? Variation swatches or product description?
b) You can choose the position of the brand on the single product in the Theme Options > WooCommerce > Shop Elementor > Brands https://prnt.sc/1vp3ogp
If you uploaded brand image then you’ll get the brand image on the single product, if you remove brand image https://prnt.sc/1vp3y15 then you’ll get just brand title there
c) You disabled the breadcrumbs for the whole site in Theme Options > Breadcrumbs https://prnt.sc/1vp4cwd So, that’s why it’s missing for the single product page too. If you want to disable breadcrumbs for the simple pages only then use page options https://prnt.sc/1vp4jcv don’t disable breadcrumbs for the whole site.
3) This is how WooCommerce filter by attribute works. We have checked with the default theme and got the same result https://prnt.sc/1vp7fu1 https://prnt.sc/1vp7ntu So, contact WooCommerce plugin support https://wordpress.org/support/plugin/woocommerce/ with this question.
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