Yeah, the start menu problem is as easy as changing the properties of the shortcut. For all SP levels, I still recommend using the original Jazz2.exe file, mainly because JJ2+ does not feature anything helpful for SP (yet) and some puzzles and tricks make use of bugs in the original JJ2 that were cut out in JJ2+.

For online multiplayer, though, JJ2+ is (nearly) a must-have.