What are the doctrinal dangers of suppressing 'Chanda' (wholesome desire) and practicing Vipassana without Piti/Sukha (Rapture/Happiness)?

I have been researching the distinction between Samatha-Vipassana (Tranquility-Insight) and Sukkha-Vipassana (Dry Insight), and I am encountering textual references that suggest serious soteriological and psychological risks when the "dry" approach is uncoupled from its ethical and emotional foundations. Specifically, I am looking for Sutta or Commentary references that address the following three doctrinal pitfalls, particularly for practitioners who may be isolated from a Sangha: - The Misunderstanding of Desire (Chanda vs. Tanha): The Brahmana Sutta (SN 51.15) establishes that Chanda (desire/zeal) is necessary to complete the path ("desire to end desire"). Is there a recognized danger of a practitioner confusing Chanda with Tanha (craving), leading to a state of "spiritual apathy" where they suppress the very volition needed to emerge from suffering? How does the Abhidhamma distinguish the function of Chanda in the Iddhipadas from the craving to be abandoned? - The Near Enemy of Equanimity (Indifference): The Visuddhimagga (Chapter IX & XX) identifies "Indifference" (aññāṇupekkhā or gehasita-upekkha) as the "near enemy" of Upekkha (Equanimity). Doctrinally, how does one distinguish between a noble "letting go" and a pathological "dissociation" or depression, particularly if the practitioner is experiencing "dry" insight without the counterbalancing factors of Piti (Rapture) or Pasada (Faith)? Are there suttas that warn against adukkhamasukha (neutral feeling) being mistaken for wisdom? - The "Salt Crystal" Dynamic and Mitigation of Kamma: The Kimatthiya Sutta (AN 11.1) links Sila (virtue) causally to Non-remorse and eventually Samadhi. Furthermore, the Lonaphala Sutta (AN 3.101) suggests that a "developed mind" (large body of water) mitigates the "salt" of kamma. If a practitioner skips the cultivation of "wet" virtues (generosity, community, active merit-making) and dives straight into "dry" observation, does the canon predict a specific type of "meditation sickness" or mental rigidity? Does the Sivaka Sutta (SN 36.21) offer a corrective to the view that all physical/mental distress during practice is "karmic purification" that must be passively endured? I am interested in whether the texts treat "Dryness" not just as a technique (no Jhana), but as a potentially dangerous deficiency in the Seven Factors of Enlightenment (specifically the lack of Piti-sambojjhanga), and if such a deficiency is linked to "Wrong Deliverance" or Niyati-ditthi (fatalism).