True Neutral Master Summoner

[Wind Chime]

Are there any weaknesses to playing a True Neutral summon monster specialist given that perhaps the biggest weakness of summoned monsters the protection spells doesn't cover true neutral meaning that your animal summons (which take your alignment) can attack them without issue.

[Stauffie]

Summoned monsters (not nature's ally) ussually get a template: celestial (good) or fiendish (evil) or resolute (lawful) or entropic (chaotic), giving elemental resistences, smite against the diagonal aligment and above 5 HD also DR. There is no true neutral template.

[Wind Chime]

"Creatures marked with an “*” always have an alignment that matches yours, regardless of their usual alignment. Summoning these creatures makes the summoning spell's type match your alignment." Summon Monster.

"If you are neutral, you may choose which template to apply to the creature"

So you can have a true neutral celestial dire tiger.

"Third, the spell prevents bodily contact by good summoned creatures" Protection Against Good.

As the celestial template doesn't mention changing the alignment or type of the creature you can have a true neutral celestial dire tiger who won't be affected by any protection spell.

[Stauffie]

Hmmm, I did not read well... I would say that a celestial template makes the dire tiger a good creature, so it cannot attack a target that is protected from good...
But I checked and it really says what you are quoting under 'summon monster', it gains your alignemt instead of its usual alignment... a true neutral celestial creature... weird.

So I guess you're right, no prtection spell would help.