I would say that will struggle to run anything, even android, I would keep the minimum CPU speed on the default which is 245MHz, with a 100MHz change you will not notice much change in battery life, but it will drasticly affect performance.

 

You can lower maximum cpu speed, it will just take longer to do things, this will lower the cpu clock when its under load, when its idle it will still be running at default, but make sure it is still above the minimum cpu speed.