The main reason sellers use Optiseller is when they can't / don't want to manage item specifics on their own.
I clicked on one of your listings for a handbag and you did a thorough job of filling out the item specifics.
For you, I don't see Optiseller helping as you already have things covered in that area.
One thing I'd suggest is switching to fixed price for many of your listings. Unless something has high demand or the value is truly unknown, most people don't want to wait a week to see if they'll win so they'll move on to another seller that offers the buy it now option.
Clothing, records, tubes, etc are all common items with fixed market values. You can use Terapeak to access sold prices from the past year if you're unsure how to set your prices without auction format.
Your collectibles have done decently with auction format along with some jewelry lots and random items. I'm not saying ditch auction format completely, just be selective and intentional about when you use it as opposed to making it the default choice.
