is there a way to edit a single members reputation?
Go to their profile and delete/add whichever reputations you want.
i mean like give them as much rep as they want
like is there a way to adjust how much rep you can give at once besides the highest amount of 2?
ACP > Users and Groups > Groups > Edit usergroups > and under "Users and Permissions tab" add your desired value in "Points to Award/Take Away:" option field.