These four ideas might be stupid, but here we go.
1.)Add encypting and decrypting functions. I know xot made them in GMLScripts but it would be nice having it in Game Maker itself to protect our data some how.
2.) I was thinking that in "Debug", There should be options that shows arrayed variables. Like "Global Arrays" and "Local Arrays" so we can see what is going on cause we can't see if our arrays are getting the right information.
3.) Make the dialog box appear in the directory you want. get_openfilename(startdir,i 4got what it said here,and here) and if you want to start at "my documents" let there be a way to do so!
This will help alot since the creators of some games put the game in "Program Files" and it would be nice to appear in another directory.
4.) Make more drawing shapes. This would be nice for effects like shooting starts. draw_star(x1,y1,x2,y2,outline), this would reduce some sprite usage. Star, diamond, trapezoid. Maybe some that others might request. Oh! and make it there be a "width" for the drawn shapes. Like draw_line_width but in the shapes. draw_rectangle_width(x1,y1,x2,y2,outline,line width) this would be more usefull when drawing stuff like a menu that clearly shows its boundary.
Just some suggestions since i have no good reasons
I agree on making a better way to put tiles! Like a shape for the section you want. Maybe we might be "copying" from another maker but it is really useful.