[elsjaako]

I'm not experienced with other CAD programs, but I think scaling stuff works fine.

If you want to scale your entire object, there's a scale part operation in the part toolbench.

But in general you wouldn't want to do this. For most real world part, the dimensions you set are based on real world requirements. E.g. These holes need to be M3 and spaced 30mm apart because that's what the part we are connecting to has, but the space to the next set of holes should scale linearly with the length growing, etc.

If you have requirements like that, you should build them into your constraints. If you do this from the start, it's usually pretty easy to make size adjustments to your model.