Welcome to the forums, Avgen. I see that you are quite new to the world of FPSC. First of all, this really doesn't bother me, but others will not tolerate swearing in your posts, especialy towards FPS Creator. Anyhow, a few things that you should do before making any thread (this thing right here) is:
1. Read the ULA (User Liscence Agreemeant) - IF yo don't you will definitely regret it.
2. Read the stickies. (Posts with stars or arrows on the symbol that are always at the top. These cfontail VITAL information for any forum goer, especialy someone who has just joined today.
3. Search. At the bottom of the threads list, there is a search box. USE IT! People will get extremely agrivated because this question has been asked WAY TOO MANY TIMES. If you simply searched, you would find the answer and not have had to make a useless thread. (mabey useless was too harsh of a word)
4. READ THE MANUAL
Now, as for your questions:
There are many great scripts out there, some of them inclusing Sensei AI. Later I will give you some links that every new person needs. Anyhow, depending on the script you use, the results will vary. Also, changing the variables in your cheracters' options will help greatly. To get to their options, simply right clicke. Yous hould get the updates, I find that the version 11 beta works quite nice. It also has two new scripts. These are more realistic. FPSC is having a huge update, basicaly, version 2.0. This will use dark AI, whick is amazing compared to FPSC's AI> I hope this sovles your problems. Also, take the time to learn how to script, that is if you want to have your enemies do stuff.
Links:
FPSFree.com
http://fpsfree.com
Peanut butterfingers site
http://www.peanutbutterfingers.co.uk/index.htm