Hey there!
I was made aware of LaunchBox just a few moment ago and am excited to see both retroachievements.org and completionist.me mentioned in this thread as i happen to be one of the (ra.org) / the sole (c.me) backend developer on those sites.
One of the reasons I'm here is to check back whether the use of the personal API Key remains on the user's client or is sent somewhere else than to retroachievements.org directly.
We were made aware that there are some online third party tools asking for the private API keys of users which are then stored in a database which is against the (unwritten, more on that below) terms of use.
I'd love to get some information on how LaunchBox handles this - and maybe work out another solution with you in case it's needed.
As for updates to ra.org's api - we just recently moved servers and are currently working on the next version, which will include a new api but with legacy support until a much later (and communicated) deprecation date.
The new version will include some sanitisation of data and UI as well as infrastructure, including proper request throttling, an OAuth server, HTTPS only and said terms of use.
The current API will remain the same until then. Feel free to contact me/us for any questions regarding the upcoming changes to ra.org - I'm sure we can work out something and maybe even enhance ra.org's integration in LaunchBox
Edit: I really like what LaunchBox offers there, glad i found out about it - keep up the good work!