i guess that if you want to hyphenate all the text, you could try to
- correctly setup the language in your styles
- enable the hyphenation while typing
- then import your text / type it
if you already have all the text in (and activating the setup above does not re-hyphenate everything), you can get a script that hyphenates all text frames (if it does not exist, you can take the one that exports all text and tweak it)
ciao
a.l.e