Most modern Non Linear Editing software (NLE) is reliably better at importing footage than older software. Odds are that anything you can import to FCP7 will also be compatible with other newer NLEs.
FCP7 was a major industry standard NLE, but Apple horribly botched the release of FCPX and lost an enormous amount of good will with customers. I work in TV and film production, and I don't have a single client that uses FCPX for serious production work. I have one remaining client still using FCP7.
The majority of my clients have moved to Adobe Premiere Pro, or are using Avid systems. Premiere tends to be used in smaller production houses and freelance environments. Avid tends to be used in larger, more collaborative environments, like big production houses and TV networks.
The advantages to you of Premiere Pro is it's cross-compatibility with After Effects. You can import Premiere edits directly into After Effects. You can use Dynamic Link to embed After Effects projects in Premiere timelines, etc.
I agree -- FCP 7 would have been a good choice 7 years ago, but not now. Go with Avid or Premiere Pro. I cut in Avid, and it's easy to get an Avid edit timeline into AE as a comp using the AAF export option in Avid, then the Pro Import option in AE.