Impundulu familiar and beast bonded witch

Hi, my NE beast bonded witch is currently at 4th lvl and I'm thinking of best improved familiar choice for 7th lvl.
But I'm not sure about some things.
1)

If its master is slain, the impundulu seizes its former master's soul, retreats to a hidden place, and consumes the soul, after which it metamorphoses over the next 24 hours into its natural form, regains all of its normal abilities, and becomes free;

At 10th-level, if the witch or her familiar is gravely injured or about to die, the soul of the dying one immediately transfers to the other’s body. The two souls share the surviving body peaceably, can communicate freely, and both retain their ability to think and reason. The host may allow the guest soul to take over the body temporarily or reclaim it as a move action. They can persist in this state indefinitely, or the guest can return to its own body (if available) by touch, transfer into a suitable vessel (such as a clone), or take over another body as if using magic jar (with no receptacle).

So let's say my witch's physical body is gravely injured or about to die and soul transfers to Impundulu as per twin soul ability. Then Nolan's (my witch) soul and Impundulu's share one body. That's understandable. But what if Nolan's physical body actually dies while his soul is together with Impundulu in its body? Can then Impundulu seize Nolan's soul? Or Impundulu can seize Nolan's soul only when it is about to go to afterlife. So essentially what does slain mean - dead body or body dead and soul departing? Basically I understand that one ability supersedes another, but I cannot come to conclusion which one. So how do they interact?

2) Impundulu familiar uses statistics for imp except DR and alignment. Does this mean Impundulu cannot have form of Imp consular? Or, can Impundulu be imp consular?

Imp Consular One in every thousand imps possesses the ability to communicate telepathically with creatures within 50 feet and the power to change its form into that of any Small or Tiny animal, as per the spell beast shape II. These imp consulars are highly prized by powerful devils, who send them to serve their favored minions or to corrupt mortals with great destinies.

An imp consular can be summoned via the Improved Familiar feat by a spellcaster of 8th level or higher. Diabolists tell of other breeds of imps with similarly specialized abilities, but if such creatures truly exist they are an especially rare lot.

3) Impundulu's base/real form is that of an avian - bird. Does that mean I can actually use my Familiar Form to beast shape into birds?

At 8th level, a beast-bonded witch may take the shape of her familiar (or a giant version of her familiar or a similar kind of animal) as if using beast shape II. For example, a witch with a rat familiar can turn into a Tiny rat, Small dire rat, or a larger rodent; one with a cat familiar can turn into a Tiny cat or a Large feline such as a tiger or lion; one with a monkey familiar can turn into a Tiny monkey or a Large gorilla, and so on. The witch can remain in animal form for a number of minutes per day equal to her level.

So what is your take on these?

The specific rules for the familiar override the general rules for the beast-bond witch.

In short if you're counting on your familiar's body for you to survive your own death, this particular familiar is a poor choice.

The specific rules for the familiar override the general rules for the beast-bond witch.

In short if you're counting on your familiar's body for you to survive your own death, this particular familiar is a poor choice.

How do you determine what's general rule and what's specific?

I see it could be both way - therefore I want to see several opinions and more rules knowledge than I have.

Also what about other questions?

With the beast bonded ability the witch does not actually die. as there was no actual death the familiar cannot seize the soul. I would assume the familiar has to be alive to do that, so if you both die you probably don't have anything to worry about.

if the familiar is specifically an imp you could possibly get an imp consular, otherwise you cannot. only having the same stats isn't in itself a justification.

as for the beast shape question, you can technically only turn into a creature that is listed in that spell, this means that ability will not work for a lot of improved familiars. Otherwise I could pick a fairy dragon and turn into any large dragon, which while cool would also probably be bad for balance.

If this is a home game one alternate interpretation is that you can turn into any animal you have as a familiar, but you can only get the boosts from beast shape 2. This works fairly well if you don't try to power game it.

Ah, another Beast-Bonded Witch thread.

TheTheos, I recommend having a look at my thread for this archetype:

The Beast-Bonded Witch Archetype : clarifications / FAQ / errata

But concerning your specific questions:

1) the 10th level ability says "gravely injured or about to die" not "has died/is slain". Thus, you jump out of your meat suit before you actually die and are not subject to being eaten.

2) Sure, why not? You can't use it for PFS, tho, so it's really up to your GM.

3) While the base form may resemble a bird, it's still an outsider. Expect to see table variation on what constitutes a "similar" form. At the very minimum, your GM should at least let you take form of your familiar's specific creature type, unless they're super stingy.