edit, copy and paste formulas; rearrange series and add components
entering a formula step by step might be a safe way to get a solid input, sometimes it is really terrifying that you can not edit it using your curosr keys and copy ans paste partys of one formula into the other; maybe a formula editor mode or something like that could help us out
also, when you want to rearrange series it wuld be great to have a some small buttons facilitating a reorder like you allready have with columns in a table
and most of all, if you want to add a component, now you have to enter the source editor and look for the beginnings and ends of the source of components; a simple small add component button woule be a great feature