It's possible but you'll need to change how the events are activated! At the moment, the seeds and watering can work because the player is activating the event when they press the action button on it. You'd have to make a parallel process that checks when the player is pressing the button and where they're standing instead.
As for the scroll wheel, that's also technically possible. I'm not sure what it is off the top of my head, but you'll need the script call that checks if the mouse wheel is being used and change that for the tool button.