Rows of pads are very common in IC packages.
An easy to program but yet very powerfull feature would be to draw a whole row of pads in one go.
So you can enter a number somewhere for the amount of pads you want.
You can enter whether you want them horizontal, vertical or slanted ( Just an enter box for degrees would suffice for all of these).
Then the row of pads stays locked together in a straight row.
If you then move one of the outer pad corners, the whole row of pads is stretched as if it was a single pad. If you move one of the inner pads, then the widht of all the pads is adjusted.
Being able to manipulate such a whole row of pads makes drawing them a lot faster, and because you mostly have to manipulate the ouside of all the pads, which covers more pixels of the picture, it is also more accurate.
A snap to a grid feature also seems sensible. At least the pitch of component pads are most often nice round numbers.
Do you have some experience with FreeCAD?
I really like the way in FreeCAD, and how parametric drawing works.
Parametric drawing means you first just draw something that vaguely resembles what you want to draw, and then later you add refinements. and these refinements can also be adjusted later individually.
In FreeCAD when you’ve drawn an object and then added a length measurement, you can simply click on the mesurement, and type a new number for the size of that object (or use the scrollwheel to adjust in 1mm steps).
I like to work exact, and am not a big fan of lining things up around pixels from some photograph.
When added a row of pads (such as the example of 5 pads on top) then I would very much like to simply type in a number to have an exact pitch of 7.5units (probably mm) between te first and the last.
Your example is a very weird footprint though. Pads 1 and 4 are symetrical, while pad 2 is 1.5 from the center line and pad 3 is 1.65 from the center line. Whe does this footprint come from? Is it from a real component?
In FreeCAD there is already a way to import a picture, and scale the picture for reverse engineering purposes. I experimented once with it and it worked pretty good to determine the size of some gears I made a photograph from.
In KiCad the existing Footprint Editor is also pretty good. If it had a way to import a picture (pdf) as background and scale it that would be much preferable to me then some web page.