To be honest, I always found the character creation rules in Lankhmar and Lankhmar Unleashed an enormous waste of space, because they don't "simulate" the setting any better than the corebook cultural backgrounds and professions : I just use the latter instead.
For Black Magic, I use the corebook sorcery rules along with the thematic manipulation and corruptions rules found page 146-147,replacing the mention "manipulation skills" by "manipulation skill". If you prefer, you can perfectly use the Black magic rules as written, the two big differences with RQII sorcery being that you now have 4 manipulation skills instead of one and one skill for every spell.
Althought I also felt pretty annoyed with Mongoose for the flawed implementation of the RQII rules, it doesn't really take a lot of work to use Lankhmar Unleashed with RQII.
For Black Magic, I use the corebook sorcery rules along with the thematic manipulation and corruptions rules found page 146-147,replacing the mention "manipulation skills" by "manipulation skill". If you prefer, you can perfectly use the Black magic rules as written, the two big differences with RQII sorcery being that you now have 4 manipulation skills instead of one and one skill for every spell.
Althought I also felt pretty annoyed with Mongoose for the flawed implementation of the RQII rules, it doesn't really take a lot of work to use Lankhmar Unleashed with RQII.