What format is the video and how are you importing it into PE7? PE7 can capture DV-AVI over firewire and split by scenes on timecode during capture. For any other format you will need to use the split by content option, PE7 will analyze the video after import and split by scene after capture.
If you have already done the Capture and all is playing fine on the Timeline, You can use the "Sissors Tool" to cut your movie into discreet Clips, exactly how you want them. Actually, you have not cut the file, just the "instance" of it on the Timeline. If you wish to reorganize these Clips, you can click on each one, and drag it to the Project Panel so your will have a representation of the Clips there. Once done, you can then do a Ctrl-a (Select All) for everything on the Timeline and hit delete. You can then bring your new instances of the Clips back to the Timeline, or to the Sceneline, and arrange them, as you desire.
It is a lot less effort, to follow Paul_LS's suggestion of doing the Capture with Scene Detect on, as it will effectively "cut" your movie into segements, that you can trim, as needed. It is so much less work, that it might pay to just do a re-Capture of your footage.
One little tip when filming: always start the camera about 4-5 sec. before any important action, and let it run for another 4-5 sec. after the action. This will help you later, when you go to add any Transitions. Each "scene" will be slightly longer, but if you use Trnaistions, you will appreciate this extra footage.