ב"ה
Well, I understand the rules a little different about initiative.

I totally agree about-
 

1. Timing Issues only occur when multiple effects, controlled by multiple players, happen simultaneously.

But I think you are wrong about -

2. These issues are resolved by active decision making on the part of the Player with Initiative.

Specifically in the initiative phase the rules indeed say-

In the rare case that a timing issue occurs, the player with the initiative decides the order.

But that rule applies only in the initiative phase.
In the action stage the rule is different and the rules say -

The player with the initiative acts first during the Action Stage, and goes first whenever you must determine the order of events

So when you need to decide the order of anything in the action stage, the one with the initiative must go first (and not decide who is going first).

ב"ה

I know that sirens are usually supposed to try to go for the long game, but when facing mages that are better at long games (such as a necromancer), I need at least some rush contingencies in a siren book. I believe the worst opponent a siren could face is a necromancer, since all of his creatures are psychic immune and he is just better at meditating in his corner with an Idol of pestilence. You don't have to be in his face on 2nd turn, but in order to defeat the necromancer you should at least move quickly towards him.


First option (the quicker one)-
[19]
1) mana crystal + double move.
[24]
2) Water Elemental + face down enchantment (probably a ballad of courage on the elemental).

3) Lesser teleport on water elemental + hawkeye (+ reveal ballad of courage). So I get to my opponent's corner by turn 3 (and possibly attack with 7 dice, and with some luck 3 more dice from pushing into a wall or pushing him away from his creatures if they are not pests).

4) Marked for death on enemy mage + hurl rock

Obviously, there are other alternatives on turn 3 and on, depending on the opponents reaction, but I think you could get the Idea of the opening (the first 2 turns are the important ones)


Second option (the slower one, which is sort of solo)-
[19]
1) Naiya + mana crystal.
[12/1]
2) Ring of tides (by naiya) + mana crystal + hawkeye.
[13/1]

Basically it is supposed to act like a battleforge opening, except that you can't move on your first turn, and Naiya only bring the water equipment (especially the ring, armor, weapon and elemental wand) but not leather pieces or things like that. Otherwise, after bringing the equipment you need, Naiya could stop being your battle forge, and become your wizard tower (casting acid balls and swells and surging waves). Of course, The possibility of casting rust is well remembered (and lullaby in case you try this opening against a non-necromancer). I must try this opening before I could know how terrible is it to miss your move on first turn.

What do you think is the best way to use the siren in a fast or middle strategy?
[I rate strategies as "Fast", "Middle" or "Long". With Long not really being an option against a necromancer (and some would say that against the druid as well).]

ב"ה
I have a double tree book, but if in turn 1 my opponent seems to go aggressive, then I don't bring the second tree.
It goes like-
[19]
1) Druid's Leaf Ring + Vine Tree (in the starting corner).
[20]
2) extra vine + Seedling Pod (from vine tree) + Samara Tree (in the close corner) + Sunfire Amulet (more life economy than mana economy, but helps as well for the 30 life mage).
[15]
3) extra vine + tanglevine on mage (if solo) or a seedling pod (ifenemy is meditating in his corner) or a vine snapper (from vine tree) + seedling pod (from samara tree) + mana flower + facedown enchantment (or rouse the beast if used vine snapper).

In the 4th turn I might bring a second mana flower.

In order to keep solo enemy mages from acid ball+force hammer my tree on turn 3 (or acid ball+fireball) I try to keep them out of reach. There are 3 major ways to try and delay them-
1) Tanglevine on deployment, better coupled with a nullify on enemy mage and/or astral anchor (which in turn can be enhanced by an arcane ward).
2) Use vinewhip staff ability in first quickcast (better be coupled with an astral anchor, now that lesser teleport is out and make the stuck condition a lot less powerfull).
3) If you have initiative (or have a nullify/jinx on enemy mage from previous rounds), then wall of thorns in deployment and then force push in first quickcast (or jet stream if you feel lucky or low on mana). You both deal some damage and force your opponent to move more in order to get in range.

Note that in the case that your opponent some how actually decide to go for your Samara tree first (the one you don't have a treebond with), you should let him do so and be glad the he actually wasted his actions and spells on it.

ב"ה
I know it's a rules question and not a strategy question, and Werekingdom already answered the rules question, but I must suggest tanlevine. Tanglevine is a conjuration, so it is not affected by nullify.

ב"ה
Best at rush is a tough question, Forcemasters, Adramelech warlocks and Straywood beastmasters are the best rushers of their types. Forcemaster to rush in melee, Adramelech warlock to rush with attack spells, and Straywood beastmasters to rush with creatures. There is a strategy known as "Johktari Rushmaster" to utilize the Johktari beastmaster's fast trait in order to make an attack spell rush with it, putting hawkeye and akiro's favor on turn 1 and then double hurl boulder on turn 2. I never tried it, but It is a well known strategy (Arcane duels have a video about it, and if I am not mistaken, They invented this strategy).

Best economy is the necromancer. I've never seen a game involving a necromancer that lasted more than 12 rounds with his opponent victorious (except for a dual between two Necromancers).

About buffing oneself, assuming you mean a mage that kill it's opponent with melee attacks it buff by bringing a good weapon + bear strength + vampirism + defensive things to make sure you are not dead before you kill the enemy mage, I think the best so far is the forcemaster (though Paladin could be better, I don't have Paladin VS Siren yet). Many mages combine buffing themselves with other things (such as bringing creatures), which makes priests and araxian crown warlocks good at such combined strategies as well.

Force Sword/Orb undoubtedly would have been Autonomous if it had existed then. As it is, they are similar, but not the same as Autonomous, which gives rise to some peculiarities such as this.

I hope to see an official ruling that agree with you. It will make more sense to me.

ב"ה
First, I just want to say that I totally share the hate of zombie brutes with you, Puddnhead.

Second, If you don't want the mana but only the actions, it will usually be better to just bring a temple of asyra that will let you bring a creature every other turn (unless you just want 2 creatures on 2nd or 3rd turn). It cost only 3 more, but give you many more actions.
What's good about the banner is that it is already channeling 2, s it gives you a mana advantage.
And obviously, if you just have loads of mana and not enough actions to do anything with it (because you melee attack for full action, and bring only small spells for quickcast and your opponent often use jinx), It is a possible play to cast it on final quickcast and bring 2 creatures to just use that mana.
With melee builds (Usually with a priest or a forcemaster), I tend to stack a load of mana during midgame, when I keep attacking but only bring an enchantment or a small attack spell. Paladins are sort of builded to be made as a melee build, so having a contingency to use when they have tons of mana and not much to do with it is actually really awsome.

ב"ה
With priests I usually take at least 2 guardian angels, so I usually take the crown of protection as well. The ability to boost creatures armor anyway is an important factor when deciding between "+5 life" and "+3 life +1 armor". for the spellbook points of a rhino hide you could bring 2 copies of crown of protection, so the only reason to take rhino hide with a priest or a priestess is for the mage.
If you are going to boost your creatures armor with the crown anyway, then +5 life is better.