Do Dvati qualify for Multiweapon Fighting?

They have 4 arms between them. A Dvati ‘character’ taking the feat has 4 arms. OTOH, of course, if you look at them as separate creatures, neither qualifies. …I’m leaning towards the first interpretation, honestly, but what are your thoughts?

“Would this actually benefit them, anyway?” I hear you asking. Actually, yes. If the ‘main hand’ attack is, for instance, an unarmed strike with the leg, both hands a free for extra attacks courtesy of Multiweapon Fighting.

How do Dvati work with Maneuvers?

So Dvati may be my new favorite race. One character with two bodies poses a number of interesting questions, and while the rules are pretty clear on how that works with spellcasting, nothing is said of other things (not covered by transparency). One such thing is bardic music. Another is maneuvers from Tome of Battle. Maneuvers/stances known seems straightforward and obvious: same for each. But then we get to using those maneuvers and stances.

I’m welcome to any answers, be they based on RAW, fluff, game balance, ease of use/fun factor, or anything else.

Note: was going to provide some preliminary thoughts myself, but since they are rapidly growing into a wall of text with its own subsections and formatting, I’m going to post them as an answer.

How do Dvati work with Incarnum?

Okay, I love Dvati, because a race that is two bodies with one soul is awesome. But I sure wish they’d clarified how they worked a little more with the non-Vancian magic systems of D&D. This marks the third in a series of questions on the race, preceded by how they work with bardic music and how they work with Tome of Battle maneuvers. Gentlebeings, how do Dvati work with Incarnum feats, meldshaping, and chakra-binding?

Obviously, each body has the same feats and knows the same soulmelds. But do they have to split the number of soulmelds they can shape between each body (as well as chakra-binds), or does each body get the full package? For either case, do they have to mirror each other or can each body have a different ‘load-out’? Or can only one body have shaped and/or bound soulmelds, like casting spells? I think it’s fair to assume they share a single essentia pool, but who spends the swift action to shift essentia around? Incarnum magic items?

My thought is that you treat them as a single character; they each have the same soulmelds shaped/bound and the same distribution of essentia at all times, but what are your thoughts? As with the previous questions, I welcome answers of any justification, from flavor to RAW to balance to fun factor.

Can Dvati bards/war chanters sing multiple songs at once?

So I just found a fascinating race called Dvati, where each member is a single soul sharing two bodies. Each one shares the same build, they split their hitpoints between them, and they have several restrictions related to spellcasting and concentration… but none for bardic music. The fact that their favored class is bard leads me to believe that this isn’t an oversight, and each Dvati is intended to be able to sing a separate song. Throw in the War Chanter prestige class and you can have one character providing the benefits of four bardic musics at once, and if you throw in Dragonsong Lyrist you (possibly/probably) get up to fourteen music effects at once (though admittedly many of the Greater Dragonsongs do not stack on the same targets).

It also looks like the concentration limitations are solely for spellcasting, and each body can not only act while the other is concentrating but concentrate on something else if they want to.

In short, the question is: am I reading this correctly?

Related: This simple question ended up becoming a full on trilogy on how Dvati work. Here’re the links to Dvati and ToB maneuvers and to Dvati and Incarnum.