Corona is pretty good at rendering text, custom fonts and all. You’re biggest headaches are likely to come from text input.
There’s currently no decent higher level built in text input functions in the sdk, so devs piece together their own input handlers.
Admittedly, it gives you some flexibility in dealing with text input events, but most devs find it difficult to work with (search the forums for text input). Some of the tougher input issues range from dealing with the onscreen keyboard, to getting perfectly consistent input text size across devices (especially when using content scaling). There’s been quite a few hacks posted in the forums to deal with just those two I think…
And I still don’t think there’s a good solution posted in the code exchange or elsewhere… (anyone found one?)