@NitroPepsi
JSON!!! You don't have to know much about it, but knowing a little about a record and table definition in JSON is very helpful in PowerApps.
Because - {name : value} is a JSON record. In PowerApps, context variables are "merged/patched" into the context of the current screen. The current screen really exists as a big ol' JSON data string. SO...the UpdateContext wants to have a record to put in the context of the screen.
So, knowing that record construct should indicate when and how to use it. You will see that construct ALL over the place, because PowerApps is so deeply tied to JSON (it is what is underneath of everything).
As for the Delete formula...if your trash can icon is going to pop up a question to "yes" or "no", then you don't want the delete formula on the icon...you want it on the Yes button. The icon would only serve to activate the popup. The Yes and No button would both deactivate the popup, but the Yes button would also perform the delete function (actually, I see you're not really deleting it, but simply tagging it as deleted.)