Yes and no
Ammo, life, armor, gp, zp, etc are server sided. What you CAN do is
Name ESP
Distance ESP
FullBright (visible ghosts)
No Recoil
No Spread
No Sway
Speed
Gravity
Location (teleporting - disconnects often, but does work)
for other hacks, D3D is good for chams (see the people one color when behind a wall, another color when in front), GPS (boxes d3d style) and a few other hacks
Additionally you can look into packet injection (WPE Pro.. rename and debug the DLL to make sure its not detected, then use that DLL from your DLL). You can use that to kick on the other team, as well as a few other useful features I'll let you brainstorm on.
For D3D hacks you will need to bypass xtrap.. or freeze the hack detected memory addresses at 0 (thats what I did.) That's not exactly a bypass, but it works!
EDIT:
Also.. when memory hacking, the game may crash at the login screen. To prevent this, have ALL hacks turned OFF by default, and only enable via hotkey - which you don't want to press until you enter the server and room, preferably after you've entered your first game