Just to let y'all know, I slipped shift-click planting and modal harvesting into the latest server restart. To plant multiple seeds, hold shift when planting, and another seed of the same sort will be placed into your hand from your inventory. To harvest multiple crops, choose Adventure -> Landscaping -> Harvest Crop, and your cursor will change; clicking on crops with that cursor will harvest them without having to first right-click on them.
The menu item for harvesting looks like the one for plowing right now. Jorb needs to fix that. It can also be argued that it should be somewhere else than in the Landscaping menu, but I couldn't think of anything better right now.
P.S. The reason for this update is primarily that I've had a horrible wrist-pain for a week now after having spent some hours tending my fields. ;)