I would love a PDF of this to test. It seems to have a solid Harry Potter basis. The class seems to work well. I can test it over the next week or so.
And, I would consider getting some help in splitting the mechanics apart from the fan material. If you make the mechanics specifically OGL and isolate the IP as fan material, it might go a long way towards soothing any potential lawyers.
For example...
Class Features
House Chosen- At first level the wizard/witch enters the Hogwarts School of Witchcraft and Wizardry. When they enter the school they must choose one of the four houses. The four house are Gryffindor, Hufflepuff, Ravenclaw, and Slytherin. Upon joining the house the receive certain benefits the benefits are as follows
Gryffindor- Gryffindor's are supposed to be brave, and courageous people. They are true to their friends and can often go into situations that are beyond their abilities. As such Gryffindor's gain a +2 morale bonus to will save against fear effects. They also gain Diplomacy as a class skill.
Hufflepuff- Hufflepuff's are people who value loyalty, hard work, and honesty. As such they gain a +2 bonus to Sense Motive checks. They also gain Sense Motive as a class skill.
Ravenclaw- Ravenclaw's value ingenuity, creativity, intelligence, and curiosity. They are often called bookworms and often spend time studying. As such, they gain an additional 4 skill points at character creation. They also, gain +2 bonus to all intelligence checks for solving questions and the like.
Slytherin- Slytherin's value cunning, ambition, sneakiness, and cleverness. They are often loathed by the peers for the things they do. As such they gain a +2 bonus to Bluff checks. They also gain Bluff as a class skill.
It clearly has IP in it. The names of the houses could be an issue. If you move the text to a fan tribute section, you could use...
"Class Features
House Chosen- At first level the wizard/witch enters the school of magic. When they enter the school they must choose one of the houses. Upon joining the house the receive certain benefits the benefits are as follows"
You can list the IP in the section, but you must clearly show it is not open gaming content. If you were to add...
{Clever Fanmade Material}Gryffindor- Gryffindor's are supposed to be brave, and courageous people. They are true to their friends and can often go into situations that are beyond their abilities. As such Gryffindor's gain a +2 morale bonus to will save against fear effects. They also gain Diplomacy as a class skill.
Hufflepuff- Hufflepuff's are people who value loyalty, hard work, and honesty. As such they gain a +2 bonus to Sense Motive checks. They also gain Sense Motive as a class skill.
Ravenclaw- Ravenclaw's value ingenuity, creativity, intelligence, and curiosity. They are often called bookworms and often spend time studying. As such, they gain an additional 4 skill points at character creation. They also, gain +2 bonus to all intelligence checks for solving questions and the like.
Slytherin- Slytherin's value cunning, ambition, sneakiness, and cleverness. They are often loathed by the peers for the things they do. As such they gain a +2 bonus to Bluff checks. They also gain Bluff as a class skill.{/Clever Fan Made Material}
...and follow the general fan fiction standards. Heck, you might even get a fan site award.
The Lexicon case was over a printed book, and the big problem with fan fiction stems from the adult fiction. So, you stand a pretty good chance of avoiding legal footwork if you avoid either printing a book or putting up pornographic stories (IMO).