1. Equivalent Resistance means more resistance means less current is flowing through the circuit.
This isn’t what equivalent resistance is referring to.
Equivalent resistance is a different way of indicating ‘total’ resistance.
EqR is similar to total resistance, but they aren’t exactly the same. Total resistance is when you have loads in series in a single circuit. The total resistance of that circuit is found just by adding the resistances of the loads.
The equivalent resistance is taking the resistance of loads in parallel and theoretically combining them into a single load, and telling us what the resistance of that single load would be.
An example of how we could use that number would be to calculate the current draw from L1 in a set of parallel circuits using I = E/R, where E is the supply voltage and R is the equivalent resistance of the parallel loads.
2. Would the rule of thumb be the equation to calculate the equivalent resistance?
No, that’s the detailed calculation. A rule of thumb is a way to estimate the number without doing any math. We teach it in that video, and you also have had to answer quiz questions about it (Maybe you got them incorrect?)