In fact, word dropping is already in full flow in tp, especially DO dropping and that especially with reflexive DOs. But that all need a little essay somewhere, with some guidelines (beyond "context will tell" which sometimes doesn't work right -- I do occasionally and out of the blue want to say that I am edible, for example). There is also the writing/speaking issue. Obviously, in written language, with quotation marks, we don't need all the 'e nimi ni' frills (or even the 'toki,' come to that), where as, in spoken language we often do. And we do need some device for indirect speech in any case. The 'nimi ni' lines is, in part, the result of the rule that foreign words (in this case quoted expressions) are adjectives and so need a modificand.
BTW, I would have said (maybe even before this discussion) 'ona li a wawa'