Fledgling DM looking for advice, pointers, wisdom, etc.

[Animal]

it doesn't even have to be a lich. if you want your party to be low-level, try a vampire. they're pretty good at fleeing the scene, especially until PCs don't hit at least mid-levels. another good side - he'll be able to slowly progress in levels as the module goes on, surprising PCs with his new abilities.
liches, on the other hand, don't usually raid the villages personally. (except in OOTS)

 

[Dannyalcatraz]

The Lich isn't so much raiding the village as he is moving from one spot to another...and the village is in his path.