First off, don't expect miracle chroma keys from HDV material. The HDV format uses 4:2:0 chroma sampling as well as a thin raster of 1440 x 1080. Whatever codec you use later isn't going to overcome the limitations of your originating format. But, it's not that bad as long if your final product is released in a smaller size. We'll get

Marianna left off the leading "h" in the link. Use this: http://avid.custkb.com/avid/app/selfservice/search.jsp?DocId=237365&Hilite=moving+files+from+pc+to+mac

All OMF media files go into the OMFI MediaFiles folder. All MXF files go into Avid MediaFiles/MXF/1. There can only be one instance of each folder on the root (topmost) directory of a hard disk. If the folders are not named exactly as specified and don't follow the path stated then the Avid won't see them and the files won't relink. Also

Your Avid Project and media files won't be overwritten if you have the option to Archive and Install when you go back to 10.4.6., however that may not be an option. Best bet would be to make a backup of your boot disk and use the migration assistant to restore applications and user folders. You can manually copy the OMFI MediaFiles or Avid MediaFiles

If your disk is formatted FAT32 rather than HFS+ you won't be able to write files larger than 2 GB.

Depends on the QT version and the disk file type. It had been a problem in the past.

You're hitting a QT file size limit. Keep the files to under 2 GB each.

It goes into the Scripts folder inside the Media Composer application folder. It will add "Send to DVD Studio Pro" to your Send to... selections on your File menu within Media Composer.

If you don't find Avid Meridian Uncompressed as an option on your other system, you can copy it from Library/Quicktime and look for any codecs that start with "Avid".

If it's a script it will show up as a shortcut on the File menu under Send to. But if you're referring to Media Composer 4.0.2 be aware that this ended up in the Xpress Pro forum.