You're looking too much into this, imo. People rave about dual tree build because they offer the maximum amount of flexibility while having both roles of the TB fulfilled: support (ice) and damage (fire).

If you go all ice, you'll have a great deal of supporting capabilities, and your team will love you. However, since you sacrifice nearly all stopping power of your own, you have effectively forced yourself to always travel with a companion or risk feeding the enemy team with your deaths should you try to fly solo for a prolonged amount of time.

If you go all fire, you present top bursting capabilities up until the very late game, and you can become a hunter of nearly all DG's, regardless of your level of support from your team. However, your lack of support options will make you less effective at producing any kind of synergy with teammates in a situation where you're outclassed(i.e. being able to win a 2v3, or buying enough time for you and your teammates to escape). Furthermore, ability-based builds (which is typically all a pure fire TB can use) pale in the face of late game uber auto attack damage and stupidly high HP pools. If the game drags on, you're in trouble.

So how about a hybrid build? Well, the cons are giving up a degree of the pro's listed above in the respective "pure" builds. The pro is having (to a degree) the best of both worlds. Common builds are frost TB's that include maxed fireball (including the lvl 15 synergy ability) which allows TB's to have a super effective opener (or finisher) while still maintaining crowd control and support abilities. While it's less common to see fire-oriented hybrids (I'm excluding people that max shatter for 1350 fireballs), one such build might include frost nova to offer snare capabilities, as well as a potential getaway skill for yourself and teammates.

As far as equipment is concerned, that depends on how you want your TB to behave and what your team and the opponent's team consists of. Personally, I pick my equipment builds entirely independently of whatever tree route I'm taking. However, if anybody has equipment builds that stand out for a particular tree, feel free to correct me here.

Oh, and to get to the assassin only favor menu, click on the other tab lined up on the left side of your favor item list (same for generals).

Hybrid is one of those things that sounds good on paper and in theorycraft, but fails in game. Once you take 1v1 out of the picture, the time it takes to switch back and forth mid-battle isn't worth it because by the time you have enough skill points to utilize both forms, your demigod himself can do a significant amount of damage auto-attacking.

good responses guys thanks.  Any high ranked hybrid players want to comment?  Looks like we are getting more solo build lovers here....its getting to look like though that they all work, and none are superior. 

My 2c, thats one of the things Im finding i like about demigod....almost every build *works*, its hard to gimp yourself. 

Ah, I'm confusing things then, it appears, looking on GameFAQs, that you are correct. Ooops

True fact about generals too I guess. 

Clan based (or similar) Pantheon could change that mindset.  Then again it's always hard to find a support class in any multiplayer game.  Rarely did anyone need another mage in WoW.  Flip to a healing class and the party invites rolled endlessly.

The real gem about Hyrbrid TB, is that he always has MORE damage he can deal.  Fireball at max range, then shift to ice for instance, and you have Ice Rain ready if the guy is close, plus ice nova if you need a second to flee.

It isn't about trying to necessarily get it all in one burst, but rather that you have such a long burst duration that the enemy can't easily shrug you off.

As for how to play hybrid TB, make sure you know when to be in which form.  This is the most important thing to learn, since getting caught off guard can be very dangerous.

It would be better if you DID use rain of ice to open on DG's actually... keep in mind the attack speed debuff it has, since you are going to have to get at least within TB's auto attack range for fire nova, and it'd be a good idea if whoever decided to start smacking you smacks you slower.

its not so much to total damage output on that Fire Nova->Fireball->Rain of Ice->Deep Freeze combo that makes it any good. it probably takes about 7 seconds to go through the motions of casting all that stuff (two of the spells have cast times, and there's a form switch in the middle). the damage output comes out to about 400 DPS, which is easily achievable by almost any DG. 

what makes it good is that you're not just tossing out that damage but also blasting the hell out of the whole area and applying some debuffs to your primary target. TB's burst damage play clears out anything near him, which is pretty unique. AoE is what Torch excels at.

Only if you are charging around solo or some such. If you stick with other players, it's pretty easy to trail in behind them and lead in with fireball then switch.

Switching during combat is only a bad idea if you're being attacked and / or are low on health.