1)
Why does the Torah write here "Asher His'halachti Lefanav," whereas by Noach it wrote "es ha'Elokim His'halech No'ach" (6:9)?
1.
Refer to 6:9:4:1 & 2.
2)
Why did Eliezer report that Avraham had said, that HaSh-m would send His angel "with you" (but 24:7 says ,"in front of you")? Why "v'Hitzli'ach Darkecha" (Avraham did not say so)?
1.
Ha'amek Davar: This was to help convince them that Rivkah was the one Avraham intended for.