Having just returned from TangON, with a wealth of news in my head and a misplaced notebook, I'm quite likely to just rush a sum of words with minimum sense - but I'll do it anyway, counting on my faithful correspondents to help me trace their heads and tails.

• The close embrace (Pablo & Noelia) - the right arm should delimit the couple's space, so in a sense, it is the reference of the leader with respect to the environment. Therefore, it should maintain a rather rigid vertical attitude relative to the movement, instead of leaning inside and outside when the follower's position shifts or twists. The hand's place can be more or less mobile however
• Contretiempo (Chicho) - ... is a step which is either lead to the follower and not followed by the leader, or the other way around. Reading back that sentence, I conclude that 1) I like it, it's smart and 2) it looks like a philosophical egg with a tail. So, let me explain it: many times, there is a symmetry between the leader's steps and the follower's, much like a mirror. That way, the pair stays close (e.g. in straight forward movement). But the leader doesn't lead with his feet, so one should find it possible to lead a step without moving their own feet, or move their feet without actually leading anything (or leading something which is not symmetrical with their movement). While the latter is usually easy, the former is much, much more subtle.
  As an example, try the following exercise: lead a sidestep,change of weight, then another sidestep in the same direction to your partner, while doing the same thing. Easy. Now, lead the same, but skip your change of weight, simply do a forward step, to the sidestep direction, while remaining twisted towards your partner. Your step is easy, her step is equally easy, but leading it can be quite tricky. Don't use your hands. A 'mystical' explanation says use your breath instead. Lead her a slight up/down movement, which is trick for 'step and collect', because it feels the same. Keep in mind that, even when done perfectly, there's a chance she will miss it, so prepare for that.
  A more advanced exercise: start with a back ocho; on the movement to your right, play a barida to her left foot, as if you would start a sanguchito, but instead, lead her the step back, change of weight and forward, in double time, on your right side. Don't do the change of weight, rebound to your left foot instead (you can do an adorno to keep track of time ;) ), then, while she steps forward and forward again, you cross twice in double time. At the end of this sequence, you will find yourself in a good position to lead her a stop signal and do a gancho to her left foot (which, if you are smart, you won't do).
• Giro without torsion (Damian & Celine, Sebastian & Mariana) - I'll try to summarize my take on the milonga workshops in several notes. The first two points are twin: 1) there is no time for the regular steps & torsion in the milonga tempo; and 2) it's very important that you take your time to do the steps, instead of making / leading them faster than they actually are. So the steps need to be very small and you will want to lead them in close embrace, to save time on the "communication" process. You will also want to cut corners - for instance, an ocho, which is usually done by pivoting the follower, will be done faster by simply crossing (behind or forward). Similarly, a linear giro will be done by leading a back cross (push the follower slightly away then pull her back shifted over her weight foot), to indicate the direction of the first step, while pitching to the direction where you want the giro to go. That is, of course, if you have enough space on the floor to do that. Which you normally don't. So you can evolve this into a normal giro, which is circular (as the name tends to indicate), therefore needs some torsion. Still, instead of actually twisting your torso, as you might normally do, all you need in order to get the job done is to twist your hips - and only just. Arguably (imho) this can be achieved better if the leader's right hand stays fixed under the follower's right arm, instead of sliding on her back, during the twisting moves. Not very comfortable at first, but it kind of grows on you. as a neat trick, lead a giro with all steps in double time, very small steps, and perform the same steps, mirrored. If done right, this is called a 'corelita'.
• Movement (Pablo & Noelia) - a very simple, but very important note: when you move, concentrate on the foot holding the weight, not on the free foot. The movement itself comes from the horizontal push into the pivot foot, that particular force is the vector, not the free foot pointing, or the mere inertia. This helps balance a lot, and allows the leader to plan respect the paradigm of leading: lead, check, then follow (i.e. as opposed to lead, step simultaneously and hope for the best)

There will never be a step, sequence, or trick in tango that will come close to matching the power of the embrace --Ney Melo.

So, what is the point of the embrace? Well, the first answer would be that we cannot single out one point above all. But here are a few candidates:

1. To connect the partners into a new entity - "The Couple"
2. To channel information from the leader to the follower and the other way around
3. To secure the necessary space under and around the partners, in relation to the other couples dancing around
4. To generate on one side energy and on the other side comfort for the two partners
5. To socialize and make the best of your expensive perfume

In more detail ...

Here are the first 10 hints:
/TODO/ Intro ...

1. It's more about listening than it is about dancing.
2. There are three steps (just three): forwards, backwards and sideways.
3. There are two roles: leader and follower.
4. There are three Tango rhythms: the Tango (classical), the Milonga and the Tango Waltz; the "New Tango" or "Tango Nuevo" can also be seen as a separate branch.
5. Tango is usually danced in a ring, following (and respecting) a counter clockwise direction.
6. The embrace is arguably the most important feature of the dance. It can be open or closed.
7. Most of the time, Tango dancers have all their weight on one foot, whose choice is not (entirely) random.
8. There is (surprisingly) such a thing as a "basic step", or "basico".
9. There are two dancing systems - parallel and crossed.
10. There are many great teachers of Tango touring the world, from which you can learn new tricks.

And now the explanations: