For your first question, you want to add a flood filter. I made a very simple alias that you can use, check this forum .

Quote:
on *:TEXT:!help:#: {
set %help $rand(1,2)
set %rdm.users $nick($chan,0)
set %rdm.choose $rand(1,%rdm.users)
set %rdm $nick($chan,%rdm.choose)
if %help == 1 { /msg $chan Help %rdm $+ with this }
if %help == 2 { /msg $chan Help %rdm $+ with that }
}
For your second question, I highlighted the your issue, remove this and you'll get it. $+ it used to make mIRC validate the value of %rdm and then put the text afterwards together with the value of %rdm.

And for your third question, what you're looking for is ACTION. Example:
Code:
on *:ACTION:*:#:{
  if ($nick == Nillen) msg # <3
}