your question is quite vast in scope. Please define suitable. If I set my frequency target to 10GHz, it may be considered suitable for my applicaiton but unrealistic in current state of technology. If multi cycle paths are missing or there are more than required it is still suitable. What exactly do you mean ?
You can certainly use tools like Conformal Constraint Designer to identify potential issues in your design constraints and that is exactly the purpose of such tool in life. I am assuming that is what you were asking
You may not need to set a max fanout. Generally, if you meet max cap and max tran, you should be fine. Max tran and cap limits are usually in the .lib files, but not always, so be sure to check. If we set a max tran in the SDC, it's usually because we want a tighter limit than what is in the .lib.