For Further Iyun
A. Rashi on 33:17 quotes the Midrash that Yaakov spent 18 months in Succot! This does not appear to be "pshat." In any event, this pirush only strengthens the question of why Yaakov did not return earlier. It does, however, slightly raise the age of Yaakov's children by the time the Shechem episode occurs, rendering this story a bit more feasible.

B. It is unclear whether Yaakov ever builds the Bet-Elokim as he had promised in 28:21. See the meforshim on that pasuk who deal with this question, as well as the meforshim here on 35:14. Nonetheless, anointing the matzeyva and calling that site Bet-El (see 35:14-15) clearly reveal Yaakov's intention to eventually build the Bet-Elokim, even though the final goal may not be realized until Bnei Yisrael conquer Eretz Canaan in the time of Yehoshua. See Devarim 12:8-12, "v'akmal."