In Illustrator, if you have points (using pen tool) or borders/stroke, you need to expand the lines so they become Vector Shapes. To do that you need to select the lines, go to Objects in the toolbar, select Expand, have both "fill" and "stroke" checked and press ok.
Scaling any vectors to remain the same size dimensions, hold "shift" before you start to scale and release "shift" only when you are satisfied with the new sizing.
You could also select the vectors, right click (using your mouse), move down to the transform tab and select "Scale". It will show as 100%, if you want to make it 10% larger then what it is now, you have to add it to the 100 (so it reads as 110%). Vise versa to scaling down, scale down 20% would be (scale to 80%). What ever size the vector is when using the scale tool the image is 100% even after you change its size.
Example, image is 1" x 1", you want it scaled by .25". Selecting the vector (100%) scaling up would be (125%). Now your vector sits at 1.25" (this is your new 100% scale). To scale back down to its 1" size you have to input (75%) not (100%).