The present subjunctive mood

Hello there,

I found a definition of the present subjunctive mood on the Internet, a part of which (the definition) I found rather confusing:

Second, it is used in formal English in clauses beginning with words such as if; although; whether and lest: If that be the case, there is little more we can do; Tie her up securely, lest she escape.

Let's ignore the fact that the use of the present subjunctive form is considered obsolete. What struck me the most were the words, which supposedly inspire the use of the subjunctive mood. I mean whether, altough or lest unlike conditionals don't really allow you to assume an unreal situation (as if does, alright, but that's about it). I would say indicative is hence more fitting. Is this just a syntax and style thing or is there some meaning and sematics behind? (Or is the definition just plain wrong?) What do you think?

Also:

To always be intending to live a new life, but never find time to set about it - this is as if a man should put off eating and drinking from one day to another till he be starved and destroyed. ~Walter Scott

In this case I can understand why the subjunctive mood would be used as we're describing a hypothetical future situation. What I don't understand, though, is, what would be the difference between the present and past subjunctive in this sentence. I believe that:

To always be intending to live a new life, but never find time to set about it - this is as if a man should put off eating and drinking from one day to another till he were starved and destroyed. ~Walter Scott

would be pretty equal as for the meaning of the sentence. Maybe the former one expresses a future hypothetical situation, while the latter is more of a present hypothetical wish? Not that there would be much of a difference in the meaning, really. Or is there? :-) What's your opinion on the matter?