For my situation,
I'm upgraded to the .73 OS when it came out, which got rid of the mic issue I had... but it never gave me the issue of dropped calls. All my calls have been smooth sailing, with no difference to the normal rate of dropped/disconnected calls.
The hourglass issue with the ringtone...
Yes, changing your ringtone to a default stock loaded one will help with the issue... but I never have difficulties having my phone load a full song as my ringtone unless I am using several applications at once (e.g. music player, Opera Mini, Messages, and whatever else my float). The phone's active memory gets bogged down a bit. Remember to fully close an application when you're done with it
As a suggestion like everyone else has said.. Power cycling makes a huge difference to the operability of any phone on a daily basis.
I have always powercycled my phones at least once per day to flush the system. With the BlackBerry, it's even more important to do so.