Is it okay to take off with weight more than the POH max gross weight?
Can you take off over gross weight? Yes, it's possible on any airplane, dependent on how far over the weight limit you are, the density altitude, how much runway you have, what obstacles are in the area and other factors. It's very easy to go above gross in a Cessna 152 with full fuel and 2 passengers, and probably happens more often than people realize or own up to. That doesn't make it a good idea, which is why pilots are trained to do weight and balance plus performance calculations before every flight. 

Besides the safety angle, taking off over gross weight could land you in trouble with the FAA even if nothing goes wrong, you can lose your ticket for that. If there was an incident your insurance may not cover damage or litigation costs.