You teach that the fact that Ham saw the nakedness of his father is reason for the curse on Canaan, but this punishment seems a bit harsh. However Lev 20:11 and Deut 27:20 interpret the term “uncovered his father’s nakedness” to mean that the son has committed adultery with his father’s wife. Is this a more plausible crime to fit in the story of Noah?
Regarding your concerns over Canaan’s curse, your proposed interpretation doesn’t fit the text given in Genesis 9.
First, the Hebrew text in Genesis 9 is very different than the words of Leviticus 20:11. In Genesis 9:22 the Hebrew for "saw" is raah while the phrase "uncovered" in Leviticus 20 is galah. Though they sound similar when translated into English, they are in fact very different thoughts in Hebrew. To see nakedness and to uncover nakedness are not at all the same action. The first involves looking upon an unclothed body, while the latter means to engage in sex.
Secondly, even if we assume that these words mean the same thing, the action described in Genesis 9 doesn't permit your conclusion. Notice that after Ham saw his father’s nakedness, the other sons walked backward to cover up his father. This statement would make no sense whatsoever if the text was describing incest between Ham and Noah’s wife. Who then would the brothers be covering and why?
Thirdly, the fact that these brothers were acting to conceal or hide nakedness confirms that the earlier mention of seeing Noah’s nakedness is describing an unclothed body, not a description of a sexual act.
The penalty against Ham’s son was so severe precisely because the actions of his father were so obscene. The fact that our culture sees little wrong with a son viewing the nakedness of his father with perverse delight simply reflects how perverse and coarse our culture has become. This is a serious offense that humiliated his father and polluted the family name. It warranted God’s firm response.
Finally, God was working in this scenario to prepare for Israel’s future in the land. With Canaan justly cursed, the land could be given to Israel in a day to come. For more information on this relationship, please continue listening to our Genesis study.