When I import a DVD I just open the VIDEO_TS folder in Windows Explorer, right click the VIDEO_TS.ifo file and select Media Center -> Import. Alternatively, right click the folder the DVD is in and do the same (easier if I wanna import multiple DVDs at once). Once imported, I rename each entry in MC from VIDEO_TS to the name of the movie. Then I right click, select Cover Art -> Add from file...
I keep all my cover art in one folder.
When importing like this, I can just play a DVD like any other video file, and it opens the disc like any DVD player. (With the warnings, menu etc. unless you remove that when you rip the DVDs.)
Sometimes when importing DVDs by right clicking the folder instead of the VIDEO_TS.ifo, I get two entries in MC, one is the VIDEO_TS and the other is a cryptic number code, and under file name it says Unknown disc or something like that. That entry I just delete, because I just get an error trying to play it. (Remember you have to go into a library view under video to delete it, not just from the Recently Imported playlist.)
Hope this helps.