Genesis ch 12, 16-18, & 21-23

1. Abram reacts the way he does before going to Egypt because he is trying to be prepared for anything before entering.  He assumes and expects the worst which is that the Egyptians will kill him and take his wife for themselves.  He thinks that because they will want Sarai no matter what, that telling them she is his sister will save the Egyptians from killing Abram. When Pharaoh finds out its his wife he doesn't kill him and make her his wife, he is confused as to why Abram lied to him about the fact that she is already his wife. Pharaoh doesn't want to keep her as his wife once he finds out that she is already Abrams.  This shows you that Abram was kind of nervous and scared about entering Egypt because he does not know the Egyptians and don't know what they're capable of doing.  He figures the fact that he and his wife are entering their land, that now they can do whatever they please with them because they are now in their territory. 

3. I wouldn't consider Abram, Sarai, and Hagar a love triangle at all.  There is no love found between Hagar and Abram.  Sarai is Abram's wife and they love one another and no one else.  The first human problem that arises is the fact that Sarai cannot bare a child and cannot birth any of Abram's children.  Because Sarai understands this and cares so greatly for Abram and wants him to have a child still even thought she cannot be pregnant, she offers Hagar to carry his child for him because she is her servant and does anything that Sarai asks. Once Hagar becomes pregnant, Sarai has second thoughts on what she thought was a good idea at the time and sort if regrets ever going through with it.  This shows that the egyptian servant has to do all that her master tells her to do even going as far as getting pregnant with her masters own husband for her.  Once Sarai is harsh to Hagar, the servant leaves. The Lord feels for Hagar and explains to her that he will work something out in her favor with the son.