Regarding sugiru ~ to exceed
I was told by my teacher that it can only be a bad thing and consequently can't be used with adjectives that are a good thing (yoi, oishi, etc). Since in French we tend to use 'trop' in casual conversation to emphasise something (eg "c'est trop bon", it's very tasty, lit. It's too tasty) she thought she'd warn us not to do that with sugiru by habit and saying such things as kawaisugiru or oishisugiru.
The thing is, in Tae Kim's Complete Guide to Japanese, he uses as an example ii->yosugiru. ii is obviously a good thing so I've got two opposite statements.
Can we actually use sugiru with "good" things? Or is it restricted to bad things as my teacher says? Or maybe the use with good things is only for cases where it's bad? ie "She's too nice to be sincere", "she's too nice for her own good" or something like that?