Ooh, that's a very good change! (Though I'm not sure how you're doing it--Kryptonian power of suggestion?) I think you're absolutely right that if Clark and Lex had been able to have a relationship not freighted by Clark's secret, things would have gone better. Also, Clark needed time to adjust to the idea that he was an alien--I think part of the reason he can be comfortable with Chloe knowing is that he's had a lot more time to adjust to it himself.

I *hope* Lex would still be interested in Clark, even without the mystery, though I do wonder. (He still also might be convinced he hit Clark with his car, of course, and eventually Clark's ability to be in the right place at the right time would be apparent).

And oh, Lex becoming Martha and Jonathan's surrogate son is really one of my favorite scenarios. (And clearly Lex's, too, if Lexmas is any indication--the fact that Jonathan was the one honoring him clearly carried a lot of weight with him).