

I use freecad for mainly functional 3D Prints, many of which I sell on Etsy and eBay. You can see my designs here: https://www.printables.com/@16bitvirtual/models
As for how to do yourbunny. For the most part, you are falling into the biggest hurdle for FreeCAD. FreeCAD has constructing geometry which cannot interfere with the model. But it also means that if you aren’t very specific with your design it will fail. For example with the Bunny you need to define in your sketch what you’d like to pad or pocket out.
Then you work on adding details
The constructor lines are why I love FreeCAD since in other software I had to be very specific on what I can add without voids being accidentally added into my model.
The bunny 20-30 minutes since I don’t use Eclipses too much, and how to do Eclipse arcs to make a solid outline. I’d say if I was more familiar it should take less time. Since this Bunny looks way rougher than I intended too, but it was a proof of concept.
The interception geometry issue was the biggest learning hurdle for FreeCAD for myself. However since moving I’ve grown to prefer it since it avoid voids being created by tiny intersections which are difficult to see. For example for the skatch bellow, if you are not careful you may miss the middle and create a random hole in your model. Had this on many of my earliest designs and spent a lot of time trying to fix it since the software wouldn’t render out the shape right.
I also I love how FreeCAD changes the color of a sketch’s lines green and a brighter green when everything is contained. I see it like a game and it forces me to think about how the shape should be rather than what’s close enough to what I need.
That said, while I was like you and worked with a single sketch and padded, pushes and constrained my way to make the model I needed. FreeCAD does like you import existing geometry into a design. In the current BETA they are allowing that geometry to even be constructor geometry to make modeling easier. So you can continue to base your current sketch upon the previous one, and it’ll update as you move along.
While it’s not in a single sketch, I found doing it this way makes it much easier for myself to maintain a model and go back into it to fix parts of it when needed.
I also know FreeCAD isn’t for everyone, and there are hurdles to move to it. But I personally found it works with my workflow, and not being tied to yearly licenses is a relief for me.