I have not had any problems with the duplicate formulas.  You may find a solution here -https://www.google.com/search?client=firefox-b-1-d&q=duplicate+formulas+in+daz+studio

Lack of Skin defects and detail can be fixed by some of these - https://www.daz3d.com/catalogsearch/result?pp=40&q=genesis+9&category%5B%5D=Characters+%3E+Modifiers+%3E+Skin+textures&s=score&p=1&guid=

This is a really good one-https://www.daz3d.com/skin-detailer-for-genesis-9-merchant-resource

Scroll through the pages and you will see different things that might interest you.

Also check out the Genesis 9 morphs.

Your duplicates could be causing the slowdowns. Something else I learned is some of the vendors create characters that reference characters or morphs that you may not own, and this slows Daz down because it is trying to locate the missing information. If this is the case, you will see it in the log file.