opa 闭环特性仿真

setting time,包括大信号和小信号,stability,UBW,PSRR,input-refered noise......

那负载特性呢?对于外电路的要求呢?需不需要仿真具体的实现放大5倍，或者积分的性能?

这些仿真都要针对你的应用了
比如一个内部的OP＆一个驱动音箱的op要求是不一样的

resistive and capacitive load simulation verification

Of course you have to simulate those.  Simulate AC and transient to see if your closed loop gain in what you want (say, 5 in your case).  If you see a high loop gain results from your AC simulation, then you should see a very close to gain of 5 in your transient simulation.
Hope this helps.