I have seen threads on this forum where folks say they have done it. There are a few effects that are on the PC that are not on the Mac. And the amount of memory, speed of the raid, kind of graphics card in use on both systems could have an effect. The best way to find out on your systems is to conduct a test before doing the actual project. That way you will know for sure.
You should be able to that! If your source files are located on a Mac formatted HDD then you need MacDrive software on Windows PC so that you can access the Mac HDD. I have done it before by saving FCP 7 project as an XML then opened the project in Premiere Pro CS5.
When I transfered from Windows 5.5 to Mac 4.0 the audio was out of sync but it did work. I had some problems saving the unused clips in the Project Manager. Maybe the preview files were too big? I transfer files back and forth between platforms with an external drive formatted as FAT32. Files can't be over 4gb.