Why did Eliezer tell Rivkah's family about Avraham's wealth?
Rashbam and Seforno: To flatter them - in that many people hoped that Yitzchak would marry their daughters, but Avraham refused them all, because he was only interested in his family in Charan.
Ha'Emek Davar: He detailed his wealth, lest they think that his Brachah is that he is happy with his portion, and he has nothing to bequeath to Yitzchak,
What is "va'Yigdal"?
Malbim: He became important (like "Asher Gidlo ha'Melech"
Malbim: He explained how Hashem blessed Avraham in three matters in which people succeed (and Haman boasted about)
Why are "va'Avadim u'Shefachos" written Chaser (without a Yud and a Vov)?
Ha'Emek Davar: This teaches that Avraham did not conduct with them so much like slaves.