1 - for the june sex scene, leave a tip on ch1 and on the date it doesnt really matter, you can be flirty or not but it should get you laid (i did one normal run and one wit hthe mod and the mod had me choose always the opposite choice i took and i still got her)
2- Katy, in ch1 if at the door you go for the non flirty option, instead of zoe fluffing you you get her, in ch2 choose to go with her to the painting thing and before entering the house get the rose in the garden (bottom right, mouse over), to get the one in ch2 you dont need the one in ch1.