Despite tackling the AIDS issue, and being populated by responsibility-free boho types who might be seriously irritating to meet in real life, City Light’s production of Rent is not overly self-important or preachy. On the contrary, it’s vibrant, absorbing and entertaining from start to finish. And despite the heaviness of its most dramatic moments, it’s also quite funny, satirizing its dreamy, self-absorbed artists at the same time it celebrates them.