Yeah, it's one of those nice little oxymorons.
So, let's break down what we're establishing here because this is after-all the hints and tips section:
1 - If possible construct scenes in a way that denotes happiness, therefore a smile, to avoid having to use 'smiled' too often.
2 - In moments when that happiness dissipates, there is cause to consider the 'quick fix' of a 'grin' or a 'smile'.
3 - Overuse leads to sloppy writing and removes the need to set up the scene in a more natural way
4 - Whilst 'smile'.'grin' can often be considered 'tags', just like 'said' ways of avoiding it should be considered when possible.
5 - Obsessively considering 'tags' that are essentially invisible words can lead to overthinking, so try to be objective in all cases.
I think it boils down to "Don't avoid a tool because others overuse it or misuse it, just don't overuse it or misuse it yourself."
As I type that bit of advice, I still NEVER want to encounter the word "amazing" again. ;-)
For your #1:
First, "smile" is really just a placeholder in this conversation, because that's the example Foxee made light of ... it could be any expression. I don't think there is any reason to avoid it IF it is a part of a whole, and fits, rather than BEING the whole.
#2: I need more of what you're getting at.
#3: I'd paraphrase as "An expression can devolve into telling, when it should most often be used as showing."
#4: Yes--expressly on the subject of dialogue tags.
#5: Yes. To continue the thought: All writing in fiction should seem natural to the reader. We shouldn't have "invisible words", also referred to as "filler words". We want color. Expressions add color when judiciously included.
Before long, you and I should condense all this and collaborate on a blog.
BTW, this discussion is giving me WAY too much reason to deflect from what I'm supposed to be doing tonight. I'm in Chapter 20, closing in on 100K words, and I have to decide if bringing up the climax and ending the novel here is too precipitous. It's definitely there to do if I decide to. I've already used up my "port sipping" allotment for the evening, and I just had to switch over to my "fake port" substitute of grape juice with a splash of vodka and coffee liquor. ;-) (If you get it just right, that combination tastes surprisingly like Cockburn's Special Reserve with less alcohol and expense. LOL)