[Brian]

Welcome to the forums! For a good overview of OmniFocus' approach to sync, check the "Synchronizing between Macs and mobile devices" page in the app's help menu material.

Contexts are a pretty useful feature once you grasp them - for example, in a meeting with a coworker I can pull out my phone, look at that person's context, and be reminded of the four things across three different projects that I need to discuss with them. It's possible to do with a flat list, but a lot harder.

That said, if you really don't have any use for contexts, there are a number of other to-do/productivity apps that take a simpler approach. (Folks that use OmniFocus tend to have task/project lists of a size that the other apps struggle with.) Off the top of my head, Things, Remember the Milk, and Toodledo are products that folks seem to enjoy using; I'm sure there are others.

Hope this helps!