Of course you make tackles as a scrumhalf. If an opposition player has the ball and you are there, what's the alternative? Would you just let him (or her) walk right by? Some scrumhalfs (Peter Stringer comes to mind) have been amongst the best tacklers in the game. What they lack in size, they make up for in aggression.
Yes
Well would you just let someone score a try and not tackle them? of course you do. What kind of question is this?
Everybody in the team tackles - and that includes you, scrumhalf. Now get to it...lol
Of course you do