Yeah "notarget" is part of the HL engine. I used it on a few maps of the DS missions :E Quite handy on maps where you must not be detected by the enemy
omg, CS singleplayer is just like a normal server that you create. of course the commands work online, just only if you create a server. adn are the admin of that server.
sure, sv_cheats 1 doesnt work becasue its CS:CZ, NOT halflife. But try "bot_kick all" or "bot_kick <name>" and it should remove the listed bot. you can add and take bots away at will, and also you canreset the gravity and stuff.
and i looked on google, and i think those "SV_cheats 1" codes only work in deleted scenes.