The pronoun waffle

No, no, it definitely is a real and serious problem that speakers of Cantonese can't distinguish between the current 1st- and 3rd-person singular pronouns in this putative IAL. I think we've got a built-in solution, though, happily: now that pronominal possession is accomplished via postposed pronouns, there's nothing stopping our using ti both as a pronoun and a demonstrative. This means we can express the following range of meaning with ti:

ti talo i puna

"this house is red"

(demonstrative specifier)

tika i puna

"this is red"

(demonstrative pronoun)

ti si mene la le Elopa

"he went to Europe"

(personal pronoun)

ka neko ti i na si mene

"his cat did not go"

(possessive pronoun)

Now the only problem is that ti sure does sound like a second-person pronoun to my Indo-European ears. *sigh* You can't please all the people all the time.