To respond only to your second question, there is a relevant passage in the gemara on Sanhedrin 74b. An objection is raised that concerns how Esther could have submitted herself publicly to Ahashverosh when we learn that it is better to die than to commit the sin of 'forbidden relations'. The terse resolution of Abayye is to suggest that "Esther was like the ground" (אסתר קרקע עולם היתה) - in other words, she was completely passive (acc. to Rashi).
Given that this doesn't appear to resolve the gemara's problem, which is how what she did could have been done publicly, Tosafot (s.v. והא אסתר פרהסיא הואי) suggest that the crime of forbidden relations only applies in such a case as the person is actively involved. They learn this out by analogy from the crime of murder, which is one of the other three transgressions that a person must die rather than commit. In an event in which a person is only passively involved in murdering another (their example is of a person being thrown onto another), they can exempt themselves by applying the principle, "מאי חזית דדמא דחבראי סומק טפי דלמא דמא דידי סומק טפי" ("What do you see [to make you think] that my friend's blood is redder? Perhaps my own blood is redder").
Based on the understanding of Tosafot, you might therefore say that Esther didn't actually commit a transgression at all.
If you're interested, Reb Chaim Brisker has a fascinating analysis of this Tosafot, in which he attempts to resolve it with the Rambam's opinion (the latter being learnt out solely from the fact that he doesn't mention this resolution to the problem). I find Reb Chaim's discourses to be considerably beyond my level of competence, personally, and if you're like me in that regard, Rabbi Yonason Hughes has an excellent book called Understanding Reb Chaim (Israel: 2010). He addresses this passage in the first discourse: "Hilchos Yesodei HaTorah".