Like any self-registered profession, the inventor can make more money by acquiring the life rewards : entrepreneur and good salesman (I forget the exact name). Through those, the inventor will get higher payments for their consigned items in the consignment shop. You might also want to get the "eccentric" life reward to make them more effective inventors.
Dragging more than one picture in the digital frame can start a slide show. If you only have one picture in the frame, everytime you load the game, you must restart the digital frame by dragging the picture in it. Better to place at least two pictures for lesser effort.
I need to ask, what does the inventor gnome look like? I've never heard of it before? Do you get it in the same places as one get gnomes or do we get it if the Sims spend a lot of time in the inventing bench (like the laundry gnome)?