Those are pretty good examples of why FUSED! should almost always be evaluator-inert.
So I guess we can assume things like array[n] would do nothing, and only mean "pick out of array" in some dialected application.
With backtick literals, 1x1 would be FUSED!, and `1x1` could be a PAIR!. But in dialected contexts you could transform between them.
Although hmm... if you want a function to be called convert-to-utf8 and that was a FUSED! naming it, it would have to be evaluator active. 
So I guess the usual exemption for languages, where if the run is all words and integers, and starts with a word, it's active...otherwise 1x1 and 1em would be evaluator active.