I don't want to say that any of these are blanket statements, of course. We can always come up with exceptions where something that is verboten works. What I think we need to realize is
1) exceptions work BECAUSE this usually doesn't work-- that is, the transgression adds meaning for the reader, who gets the alternation from conventional.
2) they work especially when the writer (intuitively or consciously) know what it's going to do for the meaning.
For example, if you are trying to write in the voice of a gushy teenaged girl, you will want to use those meaningless intensifiers:
My friend Jessie is the most awesome texter on the planet.
Modifiers can also be used for comic effect, especially the intensifiers which are really diminishers but really intensifiers. Confused? Well, this is more of an adolescent male thing, and since I just raised a couple of those, I'm familiar with that deadpan sarcastic exaggeration technique. "My mom got just a little bit mad when I crashed her car." That is, "a little" is understood to mean A WHOLE LOT.
Here's one in an article about gender disparity among Wikipedia contributors (and the truth is, as we all know it, the reason women don't contribute more to W is because we're all doing blogs :)--
(Choosing a discussion page at random, one learns that the entry on frogs once drew critical attention for including a picture of toads. It got slightly heated.)
"Slightly heated"-- we're to take that to mean that it got VERY heated, and that contrasts with the subject matter for comic effect. The diminisher meant to be an intensifier is in inverse proportion to the real joke, that people would get so exercised about frogs (though, you know, were I very into frogs, I'd be pretty annoyed if someone posted a photo of a toad).
So anyway, anytime you hear, "Don't do this, don't do that," when it comes to sentences and words, understand that there's an afterword that is only meant to be heard by the cognoscenti, the ones who can make good use of it: "But if you can achieve some cool effect, go ahead!" Know what the rules are NOT just so you can obey them, but so you can violate them in some fun way.