Is it permissible to give charity as an act of gratitude to Allah for deliverance from a calamity, or is that considered an improper التعامل with Allah and stinginess?

It is commendable for a Muslim whom Allah has saved from harm to thank Allah for this blessing with their tongue and limbs. This includes giving charity to the poor and needy. A Muslim should not limit thanking Allah only when a tribulation is removed, but rather thank Allah for all His countless blessings. Indeed, charity is among the best deeds encouraged by the Qur'an and Sunnah in all circumstances.