So I reread your initial proposal, and I think we're hung up on different areas. Sure, as you say, it would not be particularly difficult to make sex optional. However, simply not having sex on screen wouldn't make this game Safe For Work. There are times where there is nudity on screen with no sex involved (just two quick examples - the party where they play beer pong and the time we take Android to college and she hacks everyone's phones). There are also drug references that would need to be removed, dialogue to be scrubbed - not just of sex, but of other topics not considered safe for viewing in a public area, let alone work - entire events and characters to rewrite...
If your only goal here is to make all sex scenes optional, there's still a lot of work to do to eliminate references to it, but sure. It's doable. But, for me, that isn't the same as making this game safe for work. Ashley will need more than just an option to say "no" to her sexual advances to make her SFW. Maria, good lord, the number of interactions not only with the player character but with the other main and side characters that will need to be altered is staggering, to say nothing of what her job is at the start of her story. The entire dynamic with the elves has to be redone. The majority of the Info screen just... disappears. What are we replacing it with? All of the grindable "traits" are gone, and the only trackable stats for each girl that remain are Relationship Level and Affection (I assume Kisses, Hugs, and Headpats could instead be tracked for each girl and added to their pages, but this still leaves a huge hole to fill).
Let me be clear - I am not at all opposed to making all of the sex scenes optional... most of them already are. But I think you and I have different ideas about what would constitute a "SFW" version of the game.
I also personally feel that while any specific sex scene is not integral to the overall story, sex itself is woven into the very fabric of what you have created - both the world you've built and the characters you've populated it with. Excising it from the story will require approaching topics and characters in entire new ways and will necessitate a lot of rewrites that will inevitably change the story and the people we love.
It's your creation. If this is a path you truly want to follow, go for it. I'll still play and love the game. I just think maybe you're getting in deeper than you realize.