Antonio, a U13 – U19 referee, asks:
If a U12/13 player commits a dangerous tackle or a DOGSO, should I be lenient and give a yellow card or should I give a straight red and send him/her off?
This one is easy (mostly) and comes down to a simple “give the card prescribed by the Laws of the Game.” Of the two scenarios you listed, the “dangerous tackle” is straightforward — assuming by “dangerous tackle” you mean a tackle which is more serious than careless or reckless (i.e., involves excessive force or endangers the safety of an opponent), then a red card is clearly set by Law 12 (the recorded misconduct would be either “serious foul play” or “violent conduct” depending on whether the tackle was committed while challenging for the ball or not).
The only caveat here is whether the local competition authority has (as some have) forbidden the showing of cards to young players (usually limited to U-10s and below) — then you follow the Laws of the Game as modified. It is not your decision to make. Once you have identified the offense, you deal with it properly. It is important to remember in all this, particularly where fouls involving physical contact are concerned, that the send-off following the display of the red card is only partially for the purpose of punishing the offender, it is also for protecting the safety of the remaining players.
As for the DOGSO, there are complicating elements to this misconduct which have been recently introduced into the Laws of the Game as of 2016 which could affect the color of the card (what follows assumes that all DOGSO requirements — i.e., the “4 Ds” — have been met). Was the foul successful in preventing a goal and a penalty kick was awarded? Starting in 2016 and clarified further in 2017, the Law now provides that a caution should be given for the DOGSO only if the player committing the foul was engaged in an attempt to play the ball. In all other circumstances, the offender must be sent off.