Simple question needing a simple answer. Stay within the tow limits for your vehicle. These are published in the Owner's Manual.
Would a bigger truck with a bigger engine tow the load easier.......sure. Kinda an empty remark. FWIW, Tacoma is a 1/2 ton truck in a mid-size package.
Terrain will have an impact on fuel mileage, so will speed and weather.
Use your head, If the rig feels unsteady at the speed you are driving, then slow down. By all means, stay in the Right Hand lane and resist using OD, especially in hilly terrain. The Owner's Manual has good guidance on towing and vehicle management.
A key tip.....pay attention to the weights and the distribution of the weight. IIRC, the trailer tongue weight should be 10-15% of the GROSS trailer weight including the cargo in the trailer. The truck's cargo load is reduced by the tongue weight.
Air bags and other add-ons DO NOT increase the load or towing capacity.