Hi Lane, As told by Steve Premiere Elements provides the option of exporting to the Hard Disk, so that part is simple.
The second part of your question is a bit confusing. If by rendering you mean timeline rendering, then Steve has already answered your question. i.e. premiere elements edits MPEG2 natively only when it's editing HDV video. For any other video type, you will have to render it on the timeline.
However, if by rendering you mean encoding which is done at the time of exporting a file from premiere elements then this can never be avoided, not even if you are editing MPEG2 file using HDV settings.