yes when you take the battery out the processor performance is cut in half..... no idea why it does that
it's fine, it's smart about taking care of the battery. But if you dont need the battery for a long time, say a month or more, you should power it down to 50% and pop it out.
one little thing you might be concerned with though, My processor speeds cut in half when I don't have a battery in.
also go ahead and cycle the battery atleast once a month. as in full drain and full charge as back to back.