It would be better if you could convert your clips to 720*480 AVI files for better editing. MPG files are not meant to be edited and Premiere does not handle them that well either.
As far as I can tell, your computer is pretty darn fast already! Looks like there is a setting that is making your render duration go up tremendously. What are your render/export settings?
The interface is almost identical, except for the fact that FCP ‘looks’ a tad bit better. If you can edit with Premiere Pro, you will have absolutely no problems editing on FCP. Even a few of the shortcuts are similar.
If you do plan on retaining good quality footage, your best bet would be to go from a DVD player to the camera or to a TBC deck.
But, if you plan on ripping the disc and then want to edit the clips that way, take a look at https://www.videohelp.com for various tools that may help you.