Gibbs Free Energy - Maximum Work

I've been having a lot of trouble trying to truly understand Gibbs free energy from a practical perspective. I have no background in physical chemistry, but I think I have a firm grasp on many of the concepts related to Gibbs energy. That being said, I'm going to try and reason using less rigorous mathematics. I'm having a hard time bridging the concepts of Gibbs free energy and the maximum useful non-PV work that can be extracted from an ideal chemical system.

My confusion may be due to some fundamental misunderstanding, but currently my confusion follows this line of thinking:

Most chemistry texts explain that $$\Delta_\ G = wmax$$.

The most common equations for calculating $$\Delta_\ G$$ are:

eq1. $$\Delta_\ G = \Delta H - T\Delta S$$

eq.2 $$\Delta_\ G = \Delta G^\text{o} + RT\ln Q$$

Both equations essentially make the same relationship, with the difference that $$\Delta\Delta S_\mathrm{mixing}$$ is baked in with $$\Delta\ S^\text{0}$$ in eq1.

Question 1.

This may just be a notation thing, but I want to confrim that $$\Delta_\ G$$ is just an alternative notation for $$\Delta_\mathrm{r} G$$ and $$\Delta\ G^\text{o}$$ is an alternative notation for $$\Delta_\mathrm{r} G^\text{o}$$. Considering I've seen both notations used and I think its safe to assume they are.

Question 2.

If $$\Delta_\mathrm{r} G$$ or alternatively, $$\Delta\ G$$ is the slope of the Gibbs energy curve at some non-standard state defined by the reaction quotient $$Q$$ how can this value be equal to the maximum useful non-PV work. I mean it would make sense if the system were at some steady-state such that the reaction continued to generate products with no net change in product/reactant concentrations. But in reality the value of $$\Delta_\mathrm{r} G$$ will continue to change until the reaction reaches its free energy minimum.

Maybe I'm trying to get these relations to do more than they meant to do. I fully appreciate that the slope of the Gibbs energy curve will allow for determination of conditions when $$\Delta\ G = 0$$ which is useful for predicting spontaneity. I just figured (probably incorrectly) that you could for example take some known mass of reactant and from there calculate the theoretical maximum non-PV work harvested from 100% reactants --> equilibrium.

Many Thanks!