Hi @avesta,
FYI the answers to all 3 of your questions can be found in the Developers & API section of the forum.
I’ll let the Asana API team respond with more details about this string-ID change if they choose to. The one thing I feel a need to point out here is that the API team provided us developers with an incredible amount of advance notice, multiple notifications, preemptive warnings, etc. about this change.
They first announced this change over a year ago on Aug. 21, 2018:
Since then, over the past 14 or so months, they’ve continually kept developers apprised about it. Several times they temporarily made the change for short spurts of time (one hour, one day, etc.) to help surface the issue for developers that weren’t previously aware of it. They delayed making the change permanent several times, to allow even more opportunity for developers to update their code. I recommend reading through that referenced thread above for more info.
The one strong concrete recommendation I can make to you is to visit this Developers section of the forum periodically, to insure that you’re keeping abreast of upcoming API changes, as the API team always provides ample advance notice of them here.
Personally I make it a policy that whenever I create software that integrates with third-party software, I make sure to always check the third-party company’s support forum periodically, for this reason - to avoid unnecessary surprises!