I happened to be looking at R' Shteineman's sefer Ayelet haShachar, so a few parsha ideas from there:
A mussar idea: Rashi quotes the Midrash which explains “hanefesh asher asu b’Charan” as referring to converts which Avraham and Sarah attracted. Earlier in the week I saw that R’ Aviner discusses what happened to these people. He suggests that they were not geirei tzedek, as no such concept existed before matan Torah (I’m surprised he writes this so unequivocally; see Brisker Rav al haTorah, P’ Bo), but were geirei toshav who later became the chassidei umos ha’olam. He does not quote the Meshech Chocma (21:33) who also deals with this issue and writes, based on Midrash, that these converts eventually reverted to their idolatry.
R’ Shteineman notes that rather than view the time and energy Avraham expended on being makreiv these people as wasted effort because of the the lack of long-term results (at least acc. to Meshech Chochma), the Torah credits Avraham for what he accomplished. He quotes R' Yisrael Salanter and the Brisker Rav as teaching that our goal should be to simply do what is right; what the ultimate results will be, what dividends our efforts will pay, is b'yad Hashem and not our concern.
A halachic idea: Rashi writes (14:3) that the Yam haMelach during Avraham's time was not a sea, but was dry land. The gemara (Baba Basra 74b), however, writes that when Hashem created the world he made the Yam of Sdom, which is Yam haMelach, as one of the seven seas which surround Eretz Yisrael. Was it a sea from the time of creation or did it become a sea later? A simple answer is that a small sea existed from the time of creation, but expanded later in history.
This actually has a halachic nafka minah which R' Shteineman quotes from R' Elyashiv. The bracha of "oseh ma'aseh braishis" can only be recited on something created during ma'aseh braishis. Since we don't know what part of Yam haMelach was created originally and which part of the sea was a later addition, R' Elyashiv holds that the bracha can only be recited if the entire sea can be seen at one time. R' Shteineman is not convinced. Perhaps the majority of the sea existed from creation and only a small part was added later -- based on rov one should be able to recite the bracha on any part of the sea. My 2 cents: since we don't know the percentage, i.e. did rov exist from the time of creation, shouldn't we say safeik brachos l'hakeil and follow R' Elyashiv's guideline?