Is god a literal being in the sky or something else?
Most available texts seem to indicate, that all the Gnostic sects did in fact regard THE god as a real literal being in Outer Space with no origin or beginning, just simply existing.
2.) How can one truly believe in the divinity of Christ? When there is so much evidence against such a thing. Or was he just a prophet?
This relates to the issue of the Trinity. It seems the Gnostic texts do not indicate Jesus was God, with perhaps certain translation issues with the anarthrous Theos as in the standard NT canon, and they most certainly believe in other beings called "gods", often referred to as "Archons" but the word "gods" is most certainly often used. In this sense, it seems that Jesus is regarded as "a god", as the highest of the gods under the Prime uncreated god Himself, much similar to ancient Jewish Logos Theology. In the Pistis Sophia, my favorite non-canonical text which I'm going to start a whole thread on, Jesus is the physical incarnation of the first created and highest being who is given the highest authority in the Cosmos.
3.) Can one be rational as well as a believer?
I would hope a believer is 100% rational, to be an irrational believer would be rather counter-productive. Belief must be based on reason. The entire point of "Gnosis" is to have "Knowledge", not just "faith".
4.) Why is there suffering in the world?
Because of rebellion against the Prime Cause and His will for man to be godly. And because Sophia tried to emulate the Prime Cause but made an inferior being who was the cause of all sin and its resultant suffering and necessary chastisement.
5.) What does Gnosticism say about homosexuality?
In the Pistis Sophia, souls who engage in MALE (not female) acts of such will be permanently dissolved after over a century of torture at the hands of the punishing archons. Many Gnostic groups actively encouraged such acts, and many highly discouraged them. The ones that encouraged them, like the Bulgars and the Nicolations (arguably Gnostic) can be safely assumed to be the "Exception" to what was a rule of total abstinence.
6.) Are there any saints in Gnosticism?
Nope. The idea of being a "Saint" is one who has achieved the correct knowledge, acts on it, and repents of their former sins, at least in works like the Pistis Sophia.
7.) Why is no one divine or miraculous in this modern era?
There very well may be modern prophets and miracle workers on the down low. Not everyone is necessarily automatically a fraudulent "faith healer" of sorts.
8.) Are heaven and hell literally real or are they more symbolic?
In many Gnostic texts, 100% literal. The "hell" of Gnosticism is far scarier than even the standard Christian view of hell. We're talking over a century of extremely brutal punishment within an astral body that can physically feel things in between lives, at the hands of fallen archons or in the belly of the gargantuan Ancient Serpent. Heaven however is hard to describe, but it's along the idea of "returning to the Light".
9.) Is the bible meant to be taken literally?
Yes, except where it specifically implies its a parable. Some concepts like the Garden of Eden have a different account but are regarded as 100% historical events even with the different accounts.
10.) Are Gnosticism and Science compatible?
Yes. But what "science" is and what it's not is another debate.
11.) How many Gnostic organizations are there? Particularly in the United States?
There are many "new age" organizations that have somewhat Gnostic ideas that attempt to be "revivals' of ancient Gnostic ideas, but are more along the medieval developments' lines of thought than the initial dark age groups like the Valentinians and the Ophites. On that note, we don't really know what such dark age groups believed, and it's very probably that the heresy hunters lied or distorted or heard incorrect information when they wrote about them. It can be argued that ancient Nazarene ("Messianic") Judaism is the original Gnostic organization as well, though it would be far, far different than its current form of "Messianic Judaism", as Gnosticism was clearly a very Jewish-leaning movement, especially evidenced from Pistis Sophia and other works like Gospel of Philip.