Thank you so much for playing my game & leaving me such detailed, thoughtful feedback! :)
Many of your comments are quite timely, as they relate to new features I'm currently working on for the next update (Jobs & Home). The update will greatly expand on jobs & interests held by both the player and the girls. You'll be able to purchase upgrades for your home (including mobility scooters!) that enable new activities, allow girls to remain with you to the final weight stage & let you live with multiple girls at once.
So, your ideas on how these new elements could work are definitely useful to help me get them right.
I agree that the game needs dialogue with the girls, where you, as the player, can compliment/react to their weight gain. This could link in with an oft-requested feature to persuade normal girls to intentionally gain weight for you.
There are two other hose feed mixes already available in the game, but I think your formula ideas would work really well for a new cooking minigame I have planned. I want players to be able to find special ingredients that have interesting effects when used in food for the girls.
I think a 'just friends' option for the love declaration scene is a great idea. I'll include that in the next update, thank you for the suggestion. :)
Thanks too for mentioning those oversights. I'll investigate those and make sure they are improved upon in the next release.