Excellent summary of what this game is, but in your response to @Marc, you missed a couple of things relating to his first question:
Not major, but the Tailor life actually has two timing mini games and one of the other two (don't remember which).
While the Magician has a selection of elemental attacks (water/ice, earth, air, fire; it's practically the Avatar Life), the Hunter has a selection of potential secondary effects (stun, poison, sleep). It's not nearly as cool and I still prefer Magicians, but I thought I should point that out as well.
And finally, you didn't point out how you keep all the skills you learn in previous Lives (so you could wield a wand as a Blacksmith if you got the skill to in the Magician Life). You can also do challenges (quests that help you raise your rank in each Life) that don't require you to be that Life as another, then switch back to it and talk to your master to finish it. It works pretty effectively.
2. The map is really large, it really surprised me. I'd say that by walk it can take around 10-15 minutes to walk between cities, and I'm not done discovered it yet after 35 hours of gameplay.
3. There is way much more content in ACNL I'd say from what I've seen, but I didn't reach the DLC crafting content yet, so this might change, but I wouldn't think there would be more content in FL as it is not the main point of the game.
4. There is no random matchmaking sadly, it would be awesome to have it though, so this answer your second question at the same time, as there is none =(