What's the truth about the subjunctive and conditional statements, anyway?

I have generally (I would say always, but I'm not sure I always thought this) supposed that in English, uses of the subjunctive are quite limited. They include desires, judgments, etc. ("I desire that she go"), general propositions ("the very idea that he marry her"), assorted hypotheticals involving to be ("If I were mad"), and some archaic expressions that you can find in Shakespeare.

Now, in pursuing a question for someone, I find myself confronted with the possibility that many ordinary conditionals in English are in fact subjunctive-carriers. Some sources omit mention of the subjunctive; some state that it's only the "type two" conditional that takes the subjunctive ("If I got up early every morning..."); and some seem to imply that just about every conditional statement is really a subjunctive one.

My first point of concession is that, on some inspection, this so called second type might really be a subjunctive after all; if the protasis "if I were" is subjunctive, then "if I liked" must be as well.

But after this point, it gets quite murky. Do you really mean to say that a standard pluperfect conditional construction, such as "If I had gone along, I would have had fun" really contains the subjunctive mood in one or both pieces?

Now that I think about it, the indicative mood doesn't seem quite right, and surely there must be some mood happening, but the subjunctive? One thing that I am quite sure of is that in this kind of conditional, there is nothing about it that would ever differentiate it from indicative anyway: "If I had gone along" and "I had gone along" have no difference in inflection.

Does that mean that the subjunctive is imputed simply by virtue of uncertainty or doubt? That would mean that the most simple type of conditional, a present-future conditional, is subjunctive also: "If I fail, you'll hate me". The thing is, the more I inspect these fragments, the more conceivable it becomes; aren't we really saying "given that I fail", which has the look of a subjunctive to it?

However, this is where I hesitate. If mere doubt is the condition to require the subjunctive mood, that would mean that "I'm not sure if he is rich" is subjunctive, when we know that it is not, and that to try to employ it ("I'm not sure if he be rich") makes us sound like a pirate.

Maybe I have the sound of French teachers too much in my ear, telling me that the subjunctive is rarely used in English in comparison with the far more robust French equivalent. Can someone please sort this out?