1. The whithering of the state is not “relinquishing power.” The state, for Marxists, is made up of the elements of society that perform class oppression. It isn’t administration, nor is the state a unique class. Once all property is collectivized, concepts like special bodies of armed people to uphold class oppression have no need to exist, as class doesn’t exist and doesn’t have class contradictions. There’s no “abolish the state” button, it simply has no use when you have a fully collectivized and planned economy.

2. No. A democratic state that oppresses the bourgeoisie and uplifts the proletariat is not fascism. Read Blackshirts and Reds.

Marxists are absolutely leftists, if your definition of leftism is exclusionary towards Marxists and only accepts anarchists, then you’re being deeply unserious.