How many objects do you have? How large/complex are the scripts you wish to execute for each object?

I general you should try to execute the scripts as little as possible, so you normally only want to use the scripts to make decisions, for example: go there, do that, etc. When there are no decisions to make you shouldn't execute any scripts. This is true for any script language that you may choose to use.

AngelScript is fast, in fact I can honestly say that it is one of the fastest out there. This is not because of my optimization skills (that really aren't much to talk about), but more of the design decision to use statically typed variables and supporting native calling conventions for application functions. Even so it will always be much slower than code written in native code, e.g. C++.

The only way you can know if AngelScript is fast enough for your purposes is to give it a try on your own. Write up a test application that will execute the estimated number of scripts as you think you'll have in your game. Nobody can give you any numbers as the performance is highly implementation dependent, what's true for one application is not true for another.

Regards,
Andreas