The Q3 bots SUCK!! At higher levels, they basically cheat, so it's an exercise in frustration. The UT bots are awesome! They can play CTF without making you want to shoot them. I was once in a online game where bots were added to keep sides even, and I didn't even notice that more bots than people were on until I actually read the names on the teams.
Helpful hints:
1. Use the WASD key config. Using the arrow keys means you still think you're playing Doom or Tomb Raider. You have a lot of keys available around your home position that allow lots of binds that can be tripped off without moving off the directional keys.
2. DO use weapons auto-switch, but make sure you know the order of weapons (machine gun, shotgun....BFG10K) and it helps to have the Q & E keys bound to prevweap and nextweap, respectively. When you run over a weapon pickup, you'll be able to cancel the switch instantly. When I run over a gun, you HEAR the pickup and switch sounds, but the first gun stays up.
3. Use a 5-button mouse and bind as much stuff as possible. Intellipoint 4.0 allows you to map buttons to keys for just game. I have my right button bound to zoom, and the large thumb button set to Use Item. (Handy when you fall off a platform with the Teleporter or need to use the Med Kit.)
4. Learn the patterns of the weapons. You need to know how far you need to lead your target with the rocket launcher, what it's damage radius is. The spread of the shotgun, etc.
5. If you're gonna play online, get broadband or prepared to be owned...BAD! Cable or DSL is fine, but satellite ISPs are lethal. Dial-up is better.
Don't even think of stepping online until you can consistently beat every map on hardcore or nightmare.
Ignore this! Go online and get your ass kicked by HUMANS, you'll learn a lot faster than memorizing Klesk and Crash patterns. People are random and unfamiliar, the bots are always the same, with only the level of cheating they do being the variable.