Seems like a minefield to me. Impossible for a normal person with a healthy dose of humility to navigate and risky for a highly intelligent and intellectually capable person, since even if they can easily afford the children they might very easily rationalise that their wife's or their own 'psychological health' was not up to the task, never seeing that they were being selfish.
So all very subjective. I don't mind crying babies for example, to me their cries are no more stressful than the sound of birds or the wind in the trees. But I grew up around crying babies.
Someone who grew up as an only child, however, might find them terribly stressful and convince themselves that the next child was going to give them a nervous breakdown, when in reality it very probably would not.
Then what of fathers who have unstable incomes? Oil field workers for example, or real estate agents, who can make six figures when the oil price is high and suffer a decrease in income when the price is low. Should they take a high/low or hedged risk strategy when deciding the size of their family. Two children for low risk, 4 for hedged and 8-10 for high risk (assuming that oil will stay high and they will have long term well paid employment).
Simple answer is don't use contraception, don't worry too much about what happens, life has all sorts of nasty (and nice) surprises and let God provide. Most people in the Western World find a way to muddle through.
With regard to man's innate drives and emotions, responsible parenthood means that man's reason and will must exert control over them.
This I don't really understand at all. It either suggests that one can turn natural desires on an off like a tap, or hints that some sort of natural contraceptive cycle needs to be obeyed by "responsible parents".
I will hold on till her next 'safe' day. Or "let's stop having sex for a year or two", so we don't have too many children and behave "irresponsibly".
People are not this cold blooded, are they? That is why we are taught to avoid occasions of sin. Otherwise we could be in those occasions and simply be "responsible" about it. Why avoid the beach in the summertime if you can simply give up sex as a married man for one or two years or program yourself to feel like it on the 17th of the month?
Generally speaking, middle age, lack of fitness, stress, tiredness from hard work and the additional hard work of parenting will space your children out to every two to three years. That means that in a normal marriage without contraception you're going to have between 6 and 10 children depending on how early you get married.
You'll have little gaps in your schedule when you get to both be in bed at the same time and each have the energy. If those days happen to be the fertile ones then you're going to have a baby or at least a better than 10% chance.
I don't really see any alternative to this other than abstinence, which surely cannot be a general solution for most couples most of the time, or using NFP in such a way that you are diarizing when you're going to have sex.