I didn't even know this existed as a thing! I could be SO into costume design if I could treat it the same way as actual fabric costume design (which I do anyway)! Sorry, hijacked the thread a bit there, ahem, moving along...
If you do actual sewing it's definitely worth checking out a demo version of MD. I'm similar, I do lots of sewing, but the traditional way of 3d modeling doesn't work well for me.
That being said MD can be a bit frustrating. My biggest issue with it is that the documentation is horrible. You see, pricey as it is, it's a scaled down version of their other software that is for drafting patterns for actual cloths. The problem is they haven't really made to versions of the manual, or even marked what isn't a feature in MD (the way the Poser manual does with Pro vs. regular versions).
And because it's pricey a lot of the tutorials out there are for older versions.
Not to discourage you. I actually really like the software, it's just kind of a rough learning curve to really get the features down. Parts of it are just super intuitive if you've sewn, but other parts of how that works in 3D are not. If you do try it though, I'd recommend the tutorials from
Fearless Makers. They aren't all up-to-date, but they do a great job of introducing you to some important concepts.
You can import a picture of pattern pieces in MD and trace over them to make your 3d pattern pieces. However, your mileage may vary. I find it simpler to use them as a visual guide and draw the pattern pieces from scratch.
I'd agree with this. I feel like standard pattern pieces don't 'scale' well to Dawn (as an example). Most pattern pieces are made to be sized, but around sort of average dimensions. Dawn isn't really average. And when actually sewing you tend to err on the side of making things slight big or loose, knowing that you can do final adjustments to make them fit perfectly. In MD however, you can always add fabric back in if you need to.