Could I enable both of 2 configurations: Multiple rows and single cell?

Yes, you can totally enable both of these configurations at the same time, but please note that the module only allows the function of editing a single cell to work in this case.

I want to edit the quantity of configurable products but it seems that the module cannot support this feature?

You cannot edit the quantity of configurable products because this product type has inventory managed through associated products.

Does it support editing product attributes for multiple store views?

Yes, this extension does support editing attributes for multiple store views. However, not all attributes can be edited under the store view level. Only attributes with the scope as store view are editable when you filter based on store views.

Could I edit product attributes of different product types at the same time (using the function of editing multiple rows)?

Yes, you could. But some product types have specific attribute input types that cannot be edited. For example, it’s impossible to edit quantity for configurable, bundle and grouped products and even prices of these 3 product types with dynamic prices.