Parent/Child Themes and Marketpress for etsy clone...

Yet one more question from a dev working on an etsy clone for a client :slight_smile: I've been working through the TT Marketpress Frontend tutorial on creating an etsy clone. I realize this isn't produced by you guys, but uses a lot of your plugins and the tutorial has gotten a lot of traffic here, so I thought it's worth the ask... Several questions which are probably no-brainers for someone:
- is it necessary to use Framemarket as a parent theme for any given theme that I want to use Marketpress with (incl. Simplemarket - or any other theme?)
- If so, how does that even work?? (Never used a parent theme before - always has been a stand-alone on other projects.)
- Has anyone out there successfully used this tutorial with any theme other than the gridmarket one (which - no offense - I'd love to avoid). If so, any tips on customizing the header, functions, and stylesheet code they provide?

Thanks so much!