I have not fully read the Ardor concept. Will there be a new wallet for Ardor or can we still use the current updated Nxt wallet? If not, will the API change? I am currently designing a addon and I do not want to reprogram the whole stuff later again.
The api will be modified, but changes will be kept to a minimum according to core devs.
If I'm allowed to speculate, you'll be forced to provide a specific id for what child chain token you want to query, and maybe something more, but the api will be more or less the same as today.