GURPS Structural and Non-Structural (Dis)Advantages

In discussion with Alistair Windsor on GURPSnet, I came up with the following classification of (dis)advantages:

Structural

Definition:

Advantages that cannot be added and disadvantages that cannot be removed except via surgery or other high-tech/magical medicine (including chip implants). Lost points in this category generally come through injury or disease.

Typical examples:

Dwarfism, Double-Jointed, Eidetic Memory.

Behavioural

Definition:

Advantages that can be instilled and disadvantages that can be removed by intense effort. Lost points in this category generally come through fright checks.

Typical Examples:

Combat Reflexes, Phobias, Addictions, Odious Personal Habits.

Situational

Definition:

(Dis)Advantages that arise from a person's position in life. These can only be bought/bought off by changing the situation and paying the points. Lost points in this category generally come through roleplaying.

Typical Examples:

Status, Wealth, Enemies, Social Stigma.

Personal

Definition:

(Dis)Advantages that arise from a person's beliefs. Similar in effect to Situational, but the character's outlook on life must change rather than the "external" situation.

Typical Examples:

Code of Honor, Pacifism, Vow.

Here's how I'd group the (dis)advantages from the Basic Set. When I've put things like "Most Mental Disads" it means "all Mental Disads not specifically mentioned elsewhere". I've put a query by choices I think are contentious.

Attributes are a particularly troublesome case; I'd put them somewhere between Structural and Behavioural, and charge double cost but allow them to be increased through training.

Incidentally, none of my players have ever done anything except increase skills, and usually the skills I suggested based on what they did in the session. But then we don't play very often and I'm not particularly generous with points...