Stable orbits are only possible with the current value of the gravitational constant. Stronger and planets spiral inwards, weaker and they spiral outwards. Both Hawking and Sagan have mentioned this. It's not a matter of the zone of stability for orbits simply being different, there are NO stable orbits with a different value.
Chemical reactions depend on the electromagnetic force. Stronger and it makes it harder for chemical bonds to be broken, weaker and they break too easily.
Nuclear reactions (atomic stability) depend on the value of the Weak and Strong forces. Nuclear fusion in stars depend on these. Hell, matter itself depends on these. Too much Weak force and ALL atoms spontaneously decompose.
Speed of light:
The speed of light is crucial, even a .001 percent change causes the universe to fly apart, or collapse. Yes, those are gravitational issues, but gravity (and all forces) travel at the speed of light. Change this and you are directly altering the range of forces, especially during the Inflationary epoch.
There are 26 dimensionless constants that all appear to need a specific value for the universe to be habitable. That said, we simply don't know if there is a relationship between these constants that would cause them to take on the current values. You could also make the case, that of course they have these values. If they didn't we wouldn't be here to wonder about them.