Your interpretation of these Clauses is so loose
Nope, you're wrong.
My interpretation isn't loose at all. It was obtained by a fair and objective application of the well established common law rules of construction, as they stood in 1788.
Words are generally to be understood in their usual and most known signification; not so much regarding the propriety of grammar, as their general and popular use.
--Blackstone (1776)
The usual and most know signification of "general" was "Comprehending many species or individuals." The usual and most know signification of "welfare" was "happiness."
Therefore, "general welfare" means "happiness of many individuals." Thus, Congress has power to tax and spend to provide for the "happiness of many individuals" of the United States.
It appears Congress has the power to tax and spend on anything it believes will make many individuals happy.