1)
What is the meaning of "Tevel" in the current context?
1.
Rashi #1: It means 'a shame' or 'a disgrace'.
2.
Rashi #2: It means 'a mixture between the seed of the father and that of the son'.
2)
Why is The Torah more stringent (Sekilah) by a mother-in law - who is only related by marriage - than by a daughter (Sereifah) - who is a blood relative?
1.
Oznayim la'Torah: Because of the dire consequences - an angty son striking and cursing his father when he finds out.