[Charlatan]

"Substance exists and cannot be dependent on anything else for its existence."

I think that all substance relies on the makeup of the substance around it to keep it as it is. If there was no water around a fish, both having substance, the fish would lose it's shape. Not saying that a fish cannot come out of water, but then it has air around it, also having substance, substance pushing against the outside of the fish keeping it in place. So if there was only one substance it would not have anything to surround it, and there would be no life. So one substance needs another to give it form, and that means that there need be at least to substances to have the one. If there was not two substances, then there would be a full explosion of the one that is, leaving the substance to go everywhere without it controling where it went, so substance is dependant on other substances to have form, and without form there is no substance - there is nothing but one thing without substance of another kind to fight for it's place in the universe. Life therefore depends on there being many substances.

"Spinoza's mathematical and logical approach to metaphysics, and therefore ethics, concluded that emotion is formed from inadequate understanding."

Emotion is formed from our survival instinct, not from not understanding, yet not understanding is a way to trigger some emotions. Emotion is there to keep us all motivated, and is not a mistake. WIthout emotion we would not have anything driving us on to live, as living is made up of emotions and pandering to them, so without emotion we would just lie around, motionless.

"According to Spinoza, the highest virtue is the intellectual love or knowledge of God/Nature/Universe."

A virtue is something that is good, that keeps us all living and motivated in a benefitial way, so loving your fellow man is the highest virtue, and rather easily understood.