Manage content externally or internally?

I'm a technical writer planning to convert my content from an external XML source into WP. My initial plan was to import the content *continually* into WP (e.g., with each update) while authoring and managing the content externally.

However, the more I think about it, the more important it seems to manage the content directly inside of wordpress permanently. Invariably I'll end up using shortcodes and other specific WP configurations, such as the menu. These features are hard to map with a regular import. As a result, my content will end up being mixed in with some sense of proprietary wordpress markup, which may make me more married to the platform.

I saw mention of Draft and Gatherin, but I don't think any of these external CMS solutions really has a good workflow for continual publishing into WP. Am I wrong? Are there any workflows where people author outside of WP and regularly import high number of pages (e.g., 100 pages) into WP for each update?