How do I import existing products into Craft Commerce with the FeedMe or Import plugins? I get it that there are hooks, but i can't get enough inside the differences between entries and product, and actually hack together an extension for either of those plugins.
Feed Me only supports Entries at this stage. Its on the short-term roadmap in allow importing into all Elements, including Commerce Products. This cannot be achieved through hooks at the moment. Keep an eye on the plugin page.

Update: FeedMe 2.0 now supports multiple entry types, including Commerce Products: http://sgroup.com.au/plugins/feedme/getting-started/introduction