You're aggravation is misdirected. Final Cut isn't the issue, not knowing how it works is. If you want to edit files natively, Adobe Premiere Pro is the application you want to use. It's designed to do that. FCP is not....FCP requires that the media be converted to ProRes before editing.
You can do this a couple of ways:
1) Compressor (free, comes with FCP) Drop the clip into the DROPZONE, look for the ProRes 422, or even ProRes LT setting (there's a search window in the settings area, bottom right). Drag that setting onto your clip...hit SUBMIT. Yes, the file size will increase dramatically.
2) Use MPEG STREAMCLIP (free, google it). Open a clip...Here...read this: https://discussions.apple.com/thread/2059475?threadID=2059475&tstart=0 But instead of a DVD, just import the clip, and instead of choosing DV, choose ProRes.
Know that FCP is also four years old, and no longer being make, so it's pretty out of date. PPro is better, and can be had for $20 a month (Adobe is a subscription model now).