First, your portrayal of Hamas' rocket fire is inaccurate. While it is true that various actors within Gaza have been responsible for a low but continuous level of rocket attacks into Israel for a very long time, to pin the blame on Hamas is disingenuous.
Yes, I'm sure Hamas is in no way encouraging or endorsing missile attacks on Israel by groups other than itself. That's why it erected a monument to them. Obviously, they'd love nothing more than to round up those malcontents and arrest them - it's just the Israeli attacks against them in response to those rocket attacks that have prevented them from doing so in the last 13 years.
Second, you mention civilian targets. Unfortunately (or fortunately?), Hamas does not have targeting capabilities on any of their rockets. At all. The rockets are fired indiscriminately at Israel.
Well, I don't dispute that, given that Palestinian rockets not infrequently misfire and blow up their own citizens. But if you're randomly shooting a handgun into a group of a thousand people and one soldier, as far as I'm concerned, you're targeting civilians. The fact that they're firing rockets more or less randomly into a largely-civilian area hardly absolves them from shooting at civilians.
If Israel is unhappy with this arrangement, I'm sure Hamas will be more than willing to accept delivery of rockets that do have targeting capabilities.
Israel has been delivering such rockets for the last few days now.