i have a 95 runner and ya it doesnt have that great of power but it does have enough power to tow a tailer. i tow a trailer for camping and off roading and it does just fine.
welds are the most important thing on the bumper. if they are crappy then the person may not know what to set the welding machine to get maximum peneration (not good at spelling) and that = how long it will last.
if the motor is going out on you it would be a good idea to do a motor swap from your 3.0 to the 3.4 out of another runner or tocoma. there will be a couple mods to it but not much and it would cost just about the same to put a newer 3.0 in. with the 3.4 youll have alot more power and a lil...