Good questions.

Deva, modern Kemetic practice, as a whole, isn't monolithic. There are many groups that call themselves Kemetic, but most do not claim and unbroken lineage. Kemetic Orthodox kind of does, in that it's taught that Tamara Siuda does indeed carry the Kingly Ka (earthly embodiment of Heru). On lists of Nisuts made by the House of Netjer, Hekatawy I is at the end of them. But this is in Kemetic Orthodoxy, and while we refer to her in royal terms, she does have a day job, and usually asks that people call her Tamara if we're not in ritual. Then there are other Kemetic groups, and independent Kemetics. Being in Kemetic Orthodoxy, I know most about it - and I will say that no one in our faith I've spoken with belittles or derides other Kemetic groups or people, or thinks them "heretics" for not acknowledging Hekatawy I (AUS) as Nisut. Functionally, she's our teacher, and if someone else wants to worship Netjer and not be taught by Hemet (AUS), that's fine. As she as said, at least they're worshiping Netjer! That's rare as it is.
However, at the same time, it is acknowledged that Kemetic Orthodoxy religion is not, and can not be, exactly as it was in the ancient past. Even if we knew every little thing there is to know about how the ancients practiced and believed, we're modern people, we don't live in a Kemet where the Nisut has temporal/political power. But much of it is for the better, since all who practice are literate, and access to our Nisut is vastly easier than it was in ancient times. This also covers part of JA's questions, I think.
I'm kind of behind on Kemetic astrology, but the ancient Kemetics did study the stars. But, I do know that every "Egyptian zodiac" system with cards and do-dads I've encountered have absolutely no basis in ancient practices. As far as I know, the most consuming astronomical feature was Sopdet (Sirius) and its movements. The rising of Sopdet determined the calendar, and it still determines the Kemetic ritual calender. But there is little sign that there was a personal birth zodiac, as such. Relics one would find that have "Egyptian zodiacs" on them for decoration are from the Roman period, so that would obviously be influenced by them.
The afterlife is written about exhaustively on the walls of tombs in ancient Egypt. All Kemetics that I know of absolutely believe in an afterlife, usually taken place in a realm called the Duat. It's very much like life on earth, just without sickness and pain. But people do the things there that they enjoy on earth, and there is beer. Reincarnation isn't taught by Kemetic Orthodoxy, as there really isn't a concept of it from ancient Kemet. The dead are akhu, and are poetically described as being stars in the heavens. I have had conversations about reincarnation with Kemetic people, but it's generally accepted that one's ka lives on earth once. As for the ba, that could be reincarnated, but it's not something that is a central teaching, or even really normally considered.
Generally, the scenario of the Weighing of the Heart is accepted - but this is a holistic assessment, not a situation where a list of rules is adhered to, or where the deciding factor is believing that Wesir (or any other Name) loves you and is God. The scales are an apt symbol for this, because it's not any one thing, it's the general state of your being that is tested. And I believe Netjer is loving and understanding. And, while there are some ancient texts about "hells", generally, the worst punishment is being devoured by Ammit and not existing at all anymore.
JA, I was taught by teaching priests in Kemetic Orthodoxy that, while we try our best to continue the worship of Netjer as it was, it's impossible to recreate it exactly. We're just in vastly different times and situations. As such, most within the faith prefer to call it a revivalist faith, rather than reconstructionist. It's more of the spirit of devotion we hope to recreate - though many of us would love to, we're not building temples and employing a huge schedule of rotating priests. We can't celebrate the Beautiful Reunion with parades and giving a statue a boat ride down the Nile. But we do have a Nisut (and even her function has necessarily changed, as I stated), we keep to ancient standards of purity in ritual, and we read hymns and liturgy translated from ancient Egyptian sources.
Kemetic Orthodoxy acknowledges that other deities may exist for others, and even our own devotees (one can have another faith and still be Kemetic Orthodox, even Hemet (AUS) is also a Mambo) but it's not a practice to equate Kemetic Names with the gods of other cultures. When we worship Wesir, it's just Wesir (unless it's a syncretization with Sokar or Ptah, but that's a whole different discussion); we don't bring up Hades or another "underworld god" from another culture. Our practices are firmly fixed within Kemetic culture and framework. It's not Orthodoxy to mix and match, as is the tendency for eclectic Wiccans to do. Not that it's wrong, we just don't do it, and it wouldn't be called Kemetic Orthodoxy.
Yes, we have a personal relationship with Netjer, the One and Many. It's a religion of monolatry, which sees one Divine power expressing Itself in many distinct Names. It's brain-bendy, but They are both separate beings and One essence and being.
Most practitioners do worship more than one Name. As for being close to one or another, that's highly individual. Many undergo the Rite of Parent Divination, where it's determined who the parent/s of your ka is/are, as well as any beloved gods. That subject could be a whole post in itself, but experience has taught me that generally (not always) when this is done, one is generally closest to their parent deity (or deities, max of two parents). Yet, one can not feel a close connection to any deity from one's RPD and feel close to, and worship another Name entirely, and still be Kemetic Orthodox. Not a shemsu, but that's only because that entails both accepting the results of the RPD and taking a vow to serve those divined Names above others - not exclusively, but first. I am a shemset, divined daughter of Hethert, beloved of Bast-Mut and Set. I felt a deep connection with Hethert even before my RPD, so it's natural for me to hold to primary worship to Her. As for beloveds, at this point, I feel closest with Set. That may change. And Wesir has come up for devotion for me, and He's not in my divination line up. Shrines can become crowded places, and I know others that have their shrines way more crowded than me!
We have one main devotional ritual, and that is senut. It's simple, but has a definite rote formula (which is in keeping with ancient thought and practice, repeating the exact same actions and words in ritual compounds their power). Ideally, it is a daily ritual, but in practice, it's generally weekly. The more one does it, the more one reaps the benefit of its heka (power/magic). It does show devotion to Netjer, but it's really for our benefit, not Theirs. They, ultimately, don't need us - but They love us, and, in my experience, appreciate senut time and offerings.
Prayer is anything that's needed, though when it comes to "intercession", that's more of the realm of heka (magic) than prayer. Prayer is also not limited to senut or any other ritual. Prayer can be a conversation, can happen while doing everyday tasks, can be giving thanks, can be "crying on His/Her shoulder", or lots of other things, just as offerings need not be physical things - actions, especially in service of others, are wonderful offerings. Kemetic Orthodoxy doesn't really tell someone how to pray, what to offer, or what can/can't be said or done. As long as it doesn't hurt anyone, i.e., in keeping with Ma'at, it's acceptable. Any contact or communication with Netjer is seen as good. One can ask for intercession, but we also have heka, which is far more hands-on.
I hope this helps. If anything needs clarification, tell me.
Edited by lunaticheathen, 23 June 2012 - 11:57 AM.