How to repair/open damaged .nef files on mac?

Sorry if this is in the wrong place...

I am using my sisters Apple refurb Mac Air, OSX 10.8.4

Camera is a Nikon D3100

There are around 3000 pictures. Basically I made the mistake of using a crappy card reader to open my files on her computer. A zeikos one. Periodically, it would eject itself, and eventually it corrupted all 3000, some jpg pics included. I ran applexsoft SD Card Recovery and managed to recover all 3000 pictures after a couple of tries. I could see the pictures on the preview, with the watermark, and they went into the recovered file folder. I checked the file sizes and most average between 10-15 mb. Now they wont open in preview or iPhoto, saying it is unrecognizable or damaged, and does the same for the .jpgs. I have opened .nef pictures on her computer before. It's been a while since I have had a mac so I am a little fuzzy on what is supported or not. What I am wondering is:

If the preview on the recovery tool shows the pictures, is it likely that these files are salvageable?

How can I view them and what program is best?

Most of these pictures are not valuable, I only need a select number, so if I can't get all of them, would it be possible to select only the ones that I need with a particular program?

If they are indeed damaged, how can I repair them?

I've downloaded something called Stellar Mac Photo Recovery, but I don't want to run anything until I get some info...

I can't keep too much data on here, so the smallest effective program would be best...

To clarify, the pictures are currently on the laptop, not the SD card. Though they're still technically on the SD card, I am asking for help to repair the files on the computer.

Please help... I wish I could have backed these up periodically, and usually I download the most important pictures to my iPad and upload them to an img host, but I lost my iPad card reader. I'd really appreciate any help! Thank you (: