I feel a little late to the party but hope you pros wouldn't mind sharing your wisdom with a puppy like myself. Trying to mainly build a theme of my own.
Am I allowed to extend debut and use it as a theme on clients stores or do I have to write 100% of all code from scratch? I just activated the Online Store Theme editor preview and wondering if the Debut version included is "safe" to extend for a future release? Any Shopify methodology I should be aware of to extend a theme? Modifying existing code or break it out into custom snippets and include it? (hope that question made sense)
How can I do a conditional check for an app? Like, if YotPo exists - include review-yotpo.liquid else include review-standard.liquid?
Lastly, Themekit still the way to go for developing the "new" Shopify?