I’m considering changing themes. I bought one of the paid ones when my store was brand new, in 2016. In that time, I’ve heavily modded it, added and removed apps. I think it’s time for a fresh look and I’m wondering if I should just tweak the one I have again or just replace the theme with a new one. If I get a new theme, how do I do that and tweak it to my liking without either shutting down my shop or showing my customers the work in progress? If I do that, I’ll want to spend a couple weeks working on it before I reveal it to customers.
Hey mate!
Unfortunately the new theme won’t contain all the customisations that you have made to your current theme. The apps you are using however will be compatible with your new theme though, so they might just need a bit of tweaking to get them to the same point.
For development, you can add the new theme as a draft to give you some time to work on it and get it up to scratch. If you go Online Store > Themes, you can click Add Theme to add it to your store.
Once it is uploaded, if you click Actions > Preview you will be able to view the theme as if it was live, with all your data ready to go! The beauty of it is you can take your time, customise it as much as you like, break it with your main store staying up and selling! Once you are happy with it, you Publish the theme and BANG! new beautiful store ready to go 
Hope that helps!
