I think the number of players allowed on the Neg List is 35. Hamilton apparently had Tebow on their list and recently removed him, which allowed Montreal to add him to their list.
I haven't heard of any changes to the the "secret list" rules so I presume there are no limits to what positions a team has on their list. I know some teams were using almost half their 35 numbers for potential QB's. They couldn't use them all but the idea was to make the have not teams cough up a #1 draft choice for a QB off the Neg List.
The Argos and Bombers were played for suckers in the past, giving up picks for questionable talent.
Jim Barker has seemed to have changed things in Toronto since his arrival.

I have always advocated that there should be a limit of maybe 5 players for each position for more parity and save some GM's from their own stupidity. 5 QB's, 5 WR's, 5 RB's, 5 O-Line, 5 D-line, 5 LB's and 5 DB's. Total 35.