Right, since I didn't get the chance to try during beta, I had a question in mind: I noticed at the beginning of the game that you need to take the first skill of a class skill line to sort of “activate” it and start gaining XP with the skill in order to subsequently raise the class line's level. (Am I making sense?)

Now, weapon or armor skill lines don't actually require you to “buy” skills to gain experience. You will get skill line experience as long as you have them equipped and play with them, right? Active or passive skills within those skill lines only appear to have a minimum requirement of levels of the weapon/armor you are using.

Ultimately, my question is: suppose that I wanted to go with heavy armor at the beginning of the game, but decided to play as a nuker, in theory, I could just use heavy armor (or a combination of light and heavy) to raise its level and then only take the active/passive skills within the skill line that I like. Is that doable or do I need to take skill 1 in order to access skill 2, then skill 2 to access skill 3, etc.

I was given the impression that you could just select whatever skill you want as long as the requirements are met but I wanted to have confirmation; is that doable?

You can skip skills if you like. I did it.