Your question 2 is predicated on a reading of the word כשר as referring to proper spiritual value, and therefore middot. I do not believe that that interpretation is correct.
Here is Rabbi Daniel Eidensohn (author of the sefer Daat Torah) correctly translating the Rambam under discussion.
Rambam (Hilchos Ishus 3:19): Similarly a man should not marry of a child nor should he marry a woman until he has seen her and she is acceptable in his eyes. That is because if he doesn’t see her first it might turn out that she doesn’t find favor in his eyes when he does see her.
Translating the word כשר as fitting, acceptable, pleasing is not Rabbi Eidensohn's invention. Here is an entry from Jastrow:
כְּשַׁר ch. same , to be right, pleasing, fit. Targ. I Sam. XVIII, 20. Targ. Jud. XIV, 3. Targ. Ez. XV, 4; a. fr.
Since this is within the range of meaning of the word, it makes a ton of sense to say that the Rambam is consistent with his own source, rather than translating it otherwise and positing that he disagrees with his source.
In terms of checking out the rest of her body (for moles), the answer is that there is a tension between values and prohibitions. No, he may not demand to see the woman's nude body, and there are negative repercussions for his doing so. There are also negative repercussions for despising the looks of his wife. These are competing values. What the gemara discusses is in the context of not sending an agent, because he should see her, so it is talking about normal looking at a person when you interact with them. But no one suggested that this concern should override modesty considerations. Otherwise, perhaps he should sleep with her before marriage, in case he might decide that he doesn't like her!
Your question 1, whether it has to do with mekach taut -- it does not seem so from the sources. The gemara references ve'ahavta lereiacha kamocha, that you should not despise her. So it is about ethics. Further, my own suggestion is that this is a special derasha, of va'ahavta lerei'acha prime. The standard one is loving your fellow person as yourself, which naturally encompasses your wife as well. But Chazal are darshening re'acha as "your beloved" -- see Shir Hashirim, 5:2 as an example, רַעְיָתִי.