Ye-es that right, but...
...the Pro-Mini is damn small, and myself I really wouldn't like to try de-soldering anything. You don't need to remove the regulator to run it at 5V: just apply 5V to VCC. However the oscillator is a 3-pin surface-mount ceramic, which would be extremely difficult to remove.
At 17-euro each, I'd suggest investing in another board. You'll always find a use for the old one. Alternatively, you might investigate low-level programming of the timers to get the frequencies you need.