Hi!
No problem. Everyone is happy to see new faces who will probably come up with new ideas or antics eventually :) :)
Anyhow, about your new questions:
1. No, definitely no. You only really need to embark with an anvil if you either do not expect any traders at all OR if you are one of those pros who get their magma forges going before the first autumn (don't ask me how they do that, but they do, it seems).
Iron anvils are rather cheap, so you can easily buy it in the second year.
So, I strongly suggest to dump the anvil and give each of your starting dwarves 10 job skill boosts (that's the max; besides giving each either woodcutter or miner, I suggest giving them a mix of job skills; first level is enough to get them started).
Buy the animals you wish to bring.
With the rest of the points, buy food and drink (mostly drink; it doesn't spoil that fast but is consumed quite quickly).
If you embark in a map that has any vegetation besides trees, I also suggest you do not buy any seeds on embark screen if you plan to do surface farming (which is currently very easy and quick to set up). Simply harvest the bushes and use the seeds once the berries are eaten or distilled.
2. Actually, the defense of the fortress proper is already taken care of with enough traps that anyone who wishes to enter has to walk through at least about 3 traps, no matter which path is chosen.
However, especially in the beginning, you will have a lot of dwarves running around on the surface and they will not benefit from those defenses - but this is only important once you get goblin assaults.
The first thing you usually get are kobold thieves (usually around the time the caravan comes). Once a kobold thief is found, simply draft the dwarf closest to him and station her at the position where the thief is - case closed (kobold thieves are weak!).
This is the reason why the war dog is not really necessary - if the passage is narrow and you have a lot of traffic going through it, someone will spot the thief. And any dwarf is able to kill off a single kobold thief without problems.
Otherwise, make use of the terrain.
Something to note is also that all terrain is currently sloped. Beforehand, we had cliffs dropping several z-levels with no way of climbing them, but for the sake of adventure mode, they have been removed from the current version.
Walking creatures can not climb up sheer cliffs, they need stairs or ramps. You can use that in your defenses to narrow the possible approach routes for invaders. The advantage is that removing ramps is done relatively quickly, as compared to building walls, and does not require material.
Just make sure you leave the clear path for the wagon of the caravan to travel, though (mind you, clear, not straight :) ).
3. For what purpose? If you are talking about defenses, there is not really a minimum, I think, although being one level above the attackers may be advantageous :) The important thing is that if you want to put archers there, they should have LOS of as much terrain as possible.
Here is also a little bit of oddity: constructed floors can not have any buildings on them as they are already buildings themselves (no building stacking!). However, if you construct a wall, one level above, it functions as a floor, a floor which is not considered a building.
This is important, because this allows you to place ammunition stockpiles into your archery towers, or have the barracks in there as well, making absense of soldiers less common.
4. Mmmhhh, I have to admit that I don't have any concrete figures there. But if you have 2 3x3 farms working and a still and a kitchen, I think you should be fine for the first winter.
So, good luck with your fortress, and please tell us if something interesting happens or if you need more help.
Deathworks