There has been plenty of discussion on whether Ritual spells are Formulaic spells or not in the past. I would like to collect everything that is relevant. There is a good chance this won't solve the issue at all, though perhaps we'll find an answer. But it should allow SG's to see how their choice interacts with other parts of the system.
As a definition for Formulaic magic, the description includes Ritual spells. This strongly implies Rituals spells are Formulaic spells.
As such use of parentheses should be able to be removed without disturbing the meaning since the contents are there for clarification, this strongly suggests Ritual spells, as a subset of spells, are either Spontaneous (which we know they aren't) or Formulaic. Otherwise it should be written more like "when casting either Spontaneous or Formulaic spells..." with no change in word count. But this is not really definitive, especially since these parentheses are not used with similar wording elsewhere.
If Ritual spells are not a subset of Formulaic spells, then the last sentence is superfluous. This very weakly suggests Ritual spells are Formulaic spells.
This implies nothing about Ritual spells. However, the decision determines whether or not Life Boost applies to Ritual spells.
This implies nothing about Ritual spells on its own. However, as it is essentially the opposite of Poor Formulaic Magic it would seem like it should not apply to Ritual spells, weakly suggesting Ritual spells are not Formulaic. Regardless, the decision determines whether or not Method Caster applies to Ritual spells.
This implies nothing about Ritual spells directly. However, it does apply to Rituals spells, and it is a little odd for it to be the reverse of Cautious Sorcerer and have only one apply to Ritual spells. This adds a little weight to Cautious Sorcerer's suggestion that Ritual spells are Formulaic spells.
If Ritual spells are not a subset of Formulaic spells, then the last sentence is superfluous. This very weakly suggests Ritual spells are Formulaic spells.
This is actually suggestive in both directions. Ugh! Since Ritual spells are penalized, they seem to be a subset of the Formulaic spells that are difficult. However, Formulaic spells are cast as Ritual spells, so Ritual spells should be unchanged if they are Formulaic spells, yet they are changed.
It doesn't say they are any sort of subset of Formulaic spells, just like Formulaic spells. This is highly suggestive that they are two separate things because of the styling of the wording. Usually a word like "other" would be used in this phrase if Ritual spells were a subset of Formulaic spells, such as "house cats are like other felids" instead of "house cats are like felids." However, this is not definitive since we have logical situations like any given figure being both similar and congruent to itself.
This doesn't really suggest anything either way. It could be that a subset of Formulaic spells is excluded, or it could be that only two of the three sets of spells are included.
If Ritual spells are Formulaic spells, there is no need to say "and Ritual." This is suggestive that Ritual spells are not Formulaic spells.
There is no mention of Ritual spells. That Spontaneous spells are not Formulaic spells and are specifically mentioned as not needing casting tools is suggestive that Ritual spells are Formulaic spells, but this is not necessarily implied. Note that if Ritual spells are not Formulaic spells, then casting tools are not needed for Ritual spells.
First Ritual spells are separated from Formulaic spells. Then three things Ritual spells can do are disallowed for Formulaic spells. This strongly implies Rituals spells are not Formulaic spells.
Many Ritual spells are stated as being outside of the formulaic spell category. This strongly implies Rituals spells are not Formulaic spells.
