Danny. In response to your questions, here are some comments that should assist you.
1) According to the bible the angels have differences in Rank and priveleges. So why is it like that? Can God not have some equality in his own organisation in the heaven? And can we then ever hope on some equality?
Yes, the angels do have different ranks and privledges. It really is more an issue of different jobs and responsibilities. There are the ones that administer directly to God which could be thought of people in the hospitality services, hotel management, concierge, etc. The ones that do the messenger work could be thought of as the people at FedEx.
So yes, there are differences between the angels but it is no different than what we see in our lives today. Of course, there is typically a lot of cross-training done between the various types of angels so some can fill in for others when they are on other assignments or taking the day off.
2) Angels were created individual and sexless. They can not reproduce, according to the bible. Then why did God create them with sexual desires, that they felt attracted to the woman on the earth before the flood? Isn't that a bit harsh?
Well, it is true that the angels were created sexless. They are typically smooth like the Ken doll. However, the angels saw what was going on down here and wanted in. There are many things, including sexual, that we don't have an immediate desire to do. However, when we see or hear of other experiences, we may wish to try it ourselves.
Plus, being angels, they could see beneath the robes of the women and find out whose were real and who was sticking sheep skins in the tops of their robes to make them look bigger.
3) The angels are many times depicted as warriors or used as such. Why does god need myriads of them to fight? Against who?
The angels are being prepared to fight against the wicked angels at Armegeddon. The fact that there are myriads allows them to always be fresh, reduces fatigue and thus can be rotated on a regular basis. In the meantime, they can practice and put on exibhitions in the heavens.
4) Satan was the first one to fall and to sin. Why then do we always talk about the first sin being that of Adam and Eve. And how come Adam and Eve in that important question of universal souverenity, when this could all be settled with satan? Even though Satan technically sinned first, the issue of universal sovereignty does not focus around who was first. The real issue of univeral sovereignty really relates back to their own perfection. Satan, obviously, was created a perfect spirit, son of God. However, Adam and Eve though apparently created perfect obviously had an inherent flaw. Let's face it, you're not the sharpest knife in the drawer if you go out in the garden and take advice from a talking snake. Adam should just have gotten a shovel and killed the damn thing and the issue would have been resolved once and for all. However, we see the results in the world today from his lack of action. Danny, I hope this helps. I don't have my WT CD handy with all the specific references but I can provide them later. Rub a Dub