1. Is this limited to men only? (rather easy question!)
You're right. It is easy. Of course it applies to women, but I believe women experience lust in a different way than men do, and it takes more for most of them -- note, the "most" as there are exceptions to every rule -- to experience lust. More than it does men, that is, who can experience lust with the second look, which is really the one that constitutes lust in the first place. More on that in a moment.
2. To what extent is this true? Does it mean if a man pursues a relationship, but never actually goes through with it? Does it mean if he dwells on it for a set period of time? Or does it mean if you just causally look and say to yourself, "She's very desirable"?
I agree with you 9as stated later, after your OP) that lust is a sin born in the heart, and is a sin even if there is no action taken, even if no one else knows about it. Billy Graham used to say, "The first look is beyond my control, but the second look, the prolonged look, that is within my control." The implication is, taking that second look is sin, because it puts the mind, the heart and the body into a mode that they should not go, according to God's word. It can happen in a matter of seconds, but it can lead to the sin for a lifetime -- viewing pornography, becoming a sexual predator, etc. Man is rarely satisfied to remain where he is in seeking his pleasures. Thoughts may be enough at first, but then pictures and finally, acts, will be deemed necessary for him to achieve fulfillment.
3. Is this just isolated to adultry and looking at a woman to lust, or are all sins we desire to do -- but don't go through with them -- included? For example, if you plan to tell a lie, but don't go through with it, are you guilty of lying?
John wrote
1 John 2 NASB
15 Do not love the world nor the things in the world. If anyone loves the world, the love of the Father is not in him.
16 For all that is in the world, the lust of the flesh and the lust of the eyes and the boastful pride of life, is not from the Father, but is from the world.
17 The world is passing away, and also its lusts; but the one who does the will of God lives forever.
I think the passage makes it pretty clear that it isn't just sexual lust, but all lusts, that are dangerous to the spiritual walk we are to undertake.