Yeah, maximizing capability of an engine by using higher effective prop or simply increasing thrust will solve the problem…

To answer the question, 50% T/W ratio will fly but depending on airfoil characteristic. You also need smooth and longer runway. For me as another option is to have an aircraft with lower drag coefficient. Select a more aerodynamic aircraft or try evaluating existing airframe and make necessary adjustment, or if it's cost effective to make a new one would be better. Having a low drag aircraft will have higher efficiency, higher attainable speed and higher wind capability. With the help of its own mass the aircraft can fly gracefully or even develop its own energy for critical maneuver that require higher rate of climb. The downside is your aircraft might respond to your throttle request longer but just give time because once it's stabilize you don't need that much power. To slow down is not a problem even if you don’t have much drag as speed brake.

To fly an aircraft with lesser power is in fact very challenging but gives you a lot of skills and knowledge about the reality of an airplane. Continue watching airspeed, your energy management technique becomes better too…