Everyone's different. For me low carb - or Keto - means no bread, pasta, potatoes, rice or sugar in any form. Over a few years of eating this way I've found that "low carb" bread etc just doesn't work for me. Don't be afraid of fat, I have about 75% fat in my diet and it seems to work. One thing I noticed was too much protein = no weight loss. If I stick to about 80g I'm fine, anything over 100g and I don't lose (even same amount of calories).

I left all of those facebook groups. Too many idiots.

If you're low carb simply for weight loss without underlying metabolic disorder or other therapeutic reason for it, then you really have no rules to follow besides your own.

With that said, I would just be aware of your nutritional value in some things you're choosing. If you're counting calories, those few carbs from the bread might not be an issue, but hopefully the calories they claim don't take away from you eating something with nutrients to offer. That's the only thing I would consider really. I would wrap the sandwich in a romaine leaf and add avocado instead. Tons of vitamins as compared to the bread. I do support everyone finding their own way. Just something to keep in mind. I actually don't really eat vegetables either. I haven't had an avocado in months and I love them! I just don't digest veggies well, so I eat almost none. I don't eat other carbs, I just eat even fewer carbs due to lack of veggies. But, because I don't get those nutrients, I am careful to eat plenty of rare beef and not to over cook any meats to make sure to retain as much nutrition as possible.
As far as how much fat or protein... again, it's really only going to matter for those with metabolic issues. If protein is what you like, eat it. If you love butter, slather it on if you want. Many people seem to think that the eating of fat is what makes low carb work. It's just the NOT eating carbs. You don't want to eat any fake fats, you want them to be natural from animals, avocado, coconut, olive and such... and you don't want to try cutting fat by using low fat products at all, but other than that, it's meant to represent enough of your meal that keeps you satisfied until the next meal. If you're getting hungry between meals, that's a big clue there isn't enough fat or maybe not enough protein. And in some cases, that the higher carbs are creating hunger from blood sugar dropping or just carb cravings that feel like hunger.
The only other thing I would say is that while you might be able to have half a cupcake every now and then, just be sensitive to the fact that most low carbers, here anyway, are doing it to treat metabolic disorders and even binge eating and that could be hard to hear. You know what I mean? I just wouldn't flaunt it so to speak. I don't mean that I think you did, I didn't get that at all. Just thought it might be good to note it in general. That could be why some other groups get all crazy when people say they eat off plan foods sometimes. You won't find that here, but usually if someone says they ate even half a cupcake, it's followed by a binge or a fight to not binge or just feeling bad in general. There's a fine line between supporting someone's struggle getting back on the wagon and it being widely accepted to eat half cupcakes and call it a low carb diet. Being someone that identifies as a sugar addict, I had to be extremely strict in order to get past that. I even had to cut out artificial sweeteners because of the tendency to overeat.

It's kinda like talking about alcohol at an AA meeting...