Soldier's new ability

The Soldier is in (my personal opinion) a scout; he is not really designed to tank damage, heal, or act like a support.  He is meant to provide occasional pokes at enemy resistance and help his teammates to push advancing lines, which is why I enjoyed the idea of a alt healing ability, but again refer to previous point. The abilities reflect that as they allow ample movement across or above the battlefield, hidden direct attacks, and having cover/disguise.  The stink cloud is an ability that most new players will not understand, it is not  meant to kill.  While there is a variant strain to use that does deal more damage (though the cloud is smaller meaning you or your teammates are more of a target), the cloud is meant to be thrown at points where your team needs to advance or throw off the aim of enemy combatants (this is why players receive xp for smokescreen).

A good example of this is Great White North's first point.  When I play as a soldier, I follow behind my engineer so that I can quickly pick off targets that I spotted while advancing or what I will do is throw the cloud at where he needs to set up and distract enemies nearby. Usually most of the time, my fellow engineer is not seen and we are able to set up shop quickly with the rest of the team quickly behind us in tow.

In terms of abilities, I would rather see new ones that compliment the play style of a scout rather than push him into a high damage/stun territory like the confusion cloud orochi mentioned or a variant strain that causes more fog like levels in PVZ 1.