Well. Let me tell you this. My wife and I were backpacking on the coast of oregon, two twenty-something neo-hippies, very scruffy looking very homeless, in fact, we were homeless in teh fact we had no home.
We reached a point on the beach we couldn't get across, and found a trail which lead to a road.
Upon entering the neighborhood, it was VERY nice. Custom light fixtures, huge houses. I walked towered the direction we came, and found ourselves on the other side of a gate.
Gated communities give a false sense of security, especially when there are no guards. They are really nothing more than a marketting scheme to get you to feel a part of an exclusive setting. I am sure your neighborhood is nice, but the gate part is not there for your security.
My grandmother lives in Pebble Beach, the ultimate gated community. I know of a dozen or more places to avoid walking near a gate.
Should you get an alarm, if you are worried about theft, yes.