I'm looking for a game that has all of this, if it exists, or is currently being developed.
To elaborate a little on each of my points, here's what I'm looking for.
1. Action Combat - think FPS/Action controls
2. Construction - I want to build stuff, not just craft gear. I want to build a fort, walls, buildings, etc., or as much as possible.
3. Classless/Multiclass/Skill-based characters - Ideally I want to be able to make my character as unique as possible in terms of his skills and abilities. I don't want to just choose fighter, mage, or thief when I start and be exactly the same as every other character of the same class. If I can pick and choose which skills to learn, that would be perfect.
I'm also interested in games that have at least 2 of the 3 features. P2P or F2P doesn't matter. PvE or PvP doesn't matter.