1) OTA downloads are not currently supported (unless someone figured out something). there are a number of files that total more than the allowed max limit for OTA. This will likely be adjusted one day, because RIM has been approached and have talked about making OTA OS updates/reinstalls/installs.
2) Speakerphone bug fix, if you mean that the speakerphone remains either physically on (air coming out of the speaker) or the speakerphone icon remains displayed on the last call if not changed back to phone before the end of the original call, was resolved in the latest handheld update for the OS. You can get this update from TMO at www.tmobile.com/bbupgrade
The latter of the two questions was answered about 4000000 times already. The first will likely be addressed in the near future when the themes generator is released (please, don't ask when) and themes become more commonplace.