Hi, I'm going to say something here and I really hope that you don't take any offense to it. It's really not meant to be harsh, just saying it out of concern.
S&S is a difficult diet to get into, ketosis is great when it arrives but getting into it sucks! The hunger, the foggy head, the tiredness, all of it is hard. Once you get through those days it gets so much easier though but I know personally that once I'm through them I don't want to do anything to make me have to experience them again!
Unfortunately, S&S is very much an all or nothing kind of diet. You either have to commit to it completely or it just won't work. Your salad and pasta was a much healthier option than the pizza and chips (well done on resisting those, it's hard work!) but the carbs in pasta are really bad for a diet like S&S. Each thing off plan, whether it's food or alcohol, is going to set you back and probably stop you losing weight that week because of filling up your glycogen stores. Now if you're ok with very up and down losses then that's fine but I know that I couldn't cope with keep having to get back into ketosis and low losses because this diet is so hard that it wouldn't keep me motivated.
You seem like a very sociable person who enjoys eating and drinking with friends. That's something that you can't really do on this diet and I know how difficult that is. So maybe a different plan like Slimming World or just counting calories would suit you better?
Like I said, I really don't want to come across as rude or cause any offense so I hope that you haven't taken it that way.