Using a lightsaber is possible for anyone.. but, as has been addressed in other questions, it's a somewhat hard weapon to learn due to it'sits properties. (Weightless blade until it encounters things, gyroscopic effect, awareness of the location of the blade, etc.)
But that doesn't mean it's unusable for any non-Jedi... it's just not that great of a weapon, really, (just a very sharp, hot sword) UNTILuntil you add the Jedi skills.. With the phenomenal reflexes/precog/whatever granted by sensitivity to the Force, things like blocking blaster bolts become possible. So, anyone can use it, but it's risky.. and they don't gain the benefits of using it that a Jedi would. Han Solo used Luke's quite well as a knife.. but without Force sensitivity, he couldn't have blocked blaster bolts with it, except by pure luck.
As to using it via the forceForce? Yep; in the extended universe that's seen a bit. From base level use, like Mace Windu setting a pair of them to whirl around him defensively (called a Saber Barrier), to full blown telekenetic combat such as was used by Darth Traya, Darth Bane and Galen Marek.
It should be noted, though, that this takes a LOTlot of skill; in ESBThe Empire Strikes Back, Luke called his lightsaber to his hand and Han used it later as a knife.. Both are demonstrations of a very basic, and low-precision use of a tool (the Force for Luke, the Sabersaber for Han) that can be used in a much more effective way.