Oldscool, At a 3.7% grade, the difference of 5 pounds of bike weight is negligible and at 11 mph aero drag is not a large factor so having loose fitting clothing is not material - it is a few seconds or a couple of VAM. Toe clips and straps are fine as long as the shoe has a stiff sole. I see a lot of cyclists riding in soft sole shoes and I can see the shoe sole deform as the press down on the pedal. I always think that must not feel great but they are not putting in much power.

As your power and speed increase, the benefit of cycling specific clothes, shoes and pedals begin make a difference since they will be more comfortable and allow better energy transfer and aerodynamics. If you increase the % grade and length of the climb, then the weight of the bike as well as body weight become more important in increasing VAM.