Based on the information you provided you will not likely be able to enter without a waiver. You can apply for residency through your US citizen spouse, but in order to be granted permanent residence you will have to apply for a waiver for your prior overstay.
Yes I agree with the other answers. Unfortunately your brother cannot apply with your mother even though he is a minor. You will have to file a separate petition for him. If he wants to stay here with his mom and you then he will have to obtain another type of visa before his current visa expires (this is only if he is here on a visa and not enter on a visa waiver).
This is a difficult question and you should consult with an Attorney regarding your options. Yes, you are right that the correct visa is probably a B1/B2 because you have no intent on living or working in the United States, but there will be a high likelihood that they will deny it if you have a US citizen girlfriend or wife. If you do apply for the B1/B2 you want to make sure you include substantial evidence of your ties to Egypt to try to overcome the immigrant presumption.
I would not worry you need to just be patient. USCIS can take some time depending on what type of petition you submitted. You can always check the status of your petition on www.uscis.gov website or you can call the phone number on your receipt.
If you are filing an I-129F for your fiancée I highly recommend you contact an experienced immigration attorney to assist with putting together the packet to submit with the form. Some of the items you will have to provide are 1. Passport photos of you and your fiancée; 2. Evidence that you have personally met during the last 2 years; 3. Proof that you will be getting within 90 days of your fiancée's arrival to the US. This is a short list of some of the items. Please consult with an...
I would be patient. There are many reasons why your sister's received her permit before you. Not every application is the same or is given to the same officer. If you would feel more comfortable you can always call the number on the receipt, but I would not worry because there are many applicants that have not received their permits yet.