Lucius as a Death Eater
I get the feeling that the Dark Side is a matter of convenience for Lucius. It gives him more power, and more importance. It is mainly a way of gaining power, not a loyalty. For example, as soon as Voldemort went down Lucius got out of there with no second thoughts. He used the things that he had been given to assist with the things that he wanted to happen instead of having his loyalties tie him down. I don't think that anyone could argue that he had great loyalties to the Death Eaters: it's pretty clear that he doesn't.
Lucius as a Father
If you opened up a 'How to be a Good Parent' handbook, Lucius wouldn't be mentioned until the 'What NOT to do' section. He is about the exact opposite of a responsible, caring parent. He hits Draco, he ignores Draco, he instills cruel tendencies in Draco. He is arguably worse than the Dursleys, and that takes some doing.
Any fic that portrays Lucius as a caring father who is trying to help his young son is sadly mistaken. Lucius's affection only covers the part of Draco that is the family heir. He does try to make sure that Draco does well in the world, but I think that that is more about not squandering the family fortune than anything else.
Lucius as a Husband
Somehow, I don't picture Lucius as a loving husband; more as a tolerating one. Sorry, Schmergo. I wouldn't be surprised if he wasn't exactly the definition of faithful, either, though I would be surprised if he ever actually cared for someone. Any relationships would be more like flings, all of which Lucius is in complete control of and are more entertainment than anything else.
Lucius as a Redeemable Man
Nope. I don't think that that could ever fly, unless... well, if he had been dropped on his head when he was little, he might be crazy, so you could say that he never knew what he was doing... or, on a more serious note, maybe he saved someone's life in the last battle, ie Hermione. Or he might have left a Horcrux lying about deliberatly so that Voldemort would be defeated and therefore would stop crucio-ing him... yea. It'll be hard to make it work.
That's just my views, but I'd like to add another question:
Would Lucius disown any children/grandchildren who were not sorted into Slytherin, even if they were sorted into a house other than Gryfinndor, i.e. Ravenclaw?
Thanks in advance.