[Roko_foko]

make a variable that will show if the commands are disabled or not for each player.

pawn Code:

new bool:gCommandsDisabled[MAX_PLAYERS];

and on every command in the beginning put if(gCommandsDisabled[playerid]==false)return SendClientMessage(playerid,0xFF0000,"More luck next time!");

pawn Code:

OnPlayerCommandText(playerid,...)
{
    if(strcmp("/suicide",cmdtext)==0)
    {
           if(gCommandsDisabled[playerid]==true)return SendClientMessage(playerid,0xFF0000FF,"More luck next time!");
           //^^^^EDITED, was false, but have to be true
           //....
}

to enable just

pawn Code:

gCommandsDisabled[playerid]==false;// EDITED - switched enabling/disabling

to disable

pawn Code:

gCommandsDisabled[playerid]=true;