Alrighty Then!

With the new, official certificate from Chosen Security, i created a new version of GeoFeeder (with only an increased version number) with my new certificate. Then used
..\sdks\3.2.0\bin\adt -migrate -storetype pkcs12 -keystore self_signed_cert.p12 GeoFeeder_121.air GeoFeeder_121_certswitch.air
to manually wrap it with the old, self-signed signature. This way an update can be verified by the installed version (via the [...]

Adobe granted me a free code signing certificate (for 1 year):

Things are a little less “red” now.
The first mail stated i should go to Thawte (which i had used for webserver certs multiple times) and apply for a cert. Ok, setup an account, added all info, submitted on 21st of february.  On 23rd they told [...]