You can create effects for the last part. But all the others are more like just do nothing when you usually would use the disadvantage or -2/-5 buttons.
Attachment 35967
To create this I dragged the sharpshooter to the actions tab and with "right click -> add effect" added two effects.
During play, the player would declare he is using the -5 and applies the effect to them self. If it hits, apply the second effect to the character and roll damage.
There are all possible effects listed:
https://www.fantasygrounds.com/wiki/...php/5E_Effects