List of possible and impossible pharyngeals:

• Pharyngeal stops: [q̠] [ɢ̠] - the IPA shades the latter impossible, and some unofficial charts shade both, but maybe perhaps it's just a little difficult.
• Pharyngeal nasals: [ɴ̠̊] [ɴ̠] - difficult or impossible, IPA shades both impossible.
• Pharyngeal trills: [ʀ̠̊] [ʀ̠] - not shaded by the IPA, but shaded by the extIPA, maybe perhaps it's just a little difficult.
• Pharyngeal taps or flaps: [q̠̆] [ɢ̠̆] - not officially shaded, but may be shaded on some unofficial charts, perhaps just difficult.
• Pharyngeal fricatives: [ħ] [ʕ] - definitely possible and occurs in some languages like Arabic, though the latter is difficult to have frication according to Wikipedia.
• Pharyngeal lateral fricatives: [ʟ̠̊˔] [ʟ̠˔] - shaded impossible, though that quote shows that they are possible.
• Pharyngeal approximants: [ħ̞] [ʕ̞] - the latter is definitely possible and occurs in at least Danish, while the first one stays theoretically possible if no languages have it.
• Pharyngeal lateral approximants: [ʟ̠̊] [ʟ̠] - same with the pharyngeal lateral fricatives.

Very unlikely to be shaded:

• Pharyngeal fricatives: [ħ] [ʕ] = definitely possible and occurs in some languages like Arabic, though the latter is difficult to have frication according to Wikipedia.
• Pharyngeal approximants: [ħ̞] [ʕ̞] = the latter is definitely possible and occurs in at least Danish, while the first one stays theoretically possible if no languages have it.

Very unlikely to be in the white cells of the chart:

• Pharyngeal nasals: [ɴ̠̊] [ɴ̠]

Not always shaded:

• Pharyngeal stops: [q̠] [ɢ̠] - the IPA shades the latter impossible, and some unofficial charts shade both, but maybe perhaps it's just a little difficult.
• Pharyngeal trills: [ʀ̠̊] [ʀ̠] - not shaded by the IPA, but shaded by the extIPA, maybe perhaps it's just a little difficult.
• Pharyngeal taps or flaps: [q̠̆] [ɢ̠̆] - not officially shaded, but may be shaded on some unofficial charts, perhaps just difficult.
• Pharyngeal lateral fricatives: [ʟ̠̊˔] [ʟ̠˔] - shaded impossible, though that quote shows that they are possible.
• Pharyngeal lateral approximants: [ʟ̠̊] [ʟ̠] - same with the pharyngeal lateral fricatives.