I know Old Dog hates me for this, but the Alyssa path is one of those that I think is a waste of time. Since it's not a requirement for any of the main LIs, it's one of the paths I argue can be removed in order to speed the game up. Technically Nat also falls into that category.
That "cute blonde" is Julia btw. Whom I sometimes refer to as Little Precious Jules.
Curious that two of the scenes you mentioned are mutually exclusive.
Alyssa is one of few serious potential romantic LI's that Sophia could end up if she splits from Liam - because L&P seems most interested in offering Sophia a whole host of teenage LI's with (in no particular order) Ellie, Julia, Dylan, Sam, Zac (and maybe even Aiden).
If Rllie / Patricia are the likeliest to have lesbian / bisexual sex with Sophia, Alyssa is also the likeliest to do so in non-incestuous way.
Again Alyssa has been consistently in the top five or six favourites in L&P's Patreon polls (along with from memory Dylan, Ellie, Sam and Aiden.