Home hobbyist here. I design aftermarket and some actual sellable models for the scale model crowd, mostly garage kit type stuff, sold via Shapeways. Let me try to give you my home hobbyist perspective. For myself, at least, interoperability is the major issue. We're often trading CAD files between each other, and with several folks all using different CAD programs, that becomes an issue! We don't need the sheet metal features, for example. We do need better import/export capabilities, like an STL import function that actually works. In other words, keep Alibre Alibre, just disable the higher end machining features that home hobby types typically don't use. Add more and better import/export features. I do like the drawings, though - keep those - as I use that feature to send real 1:1 scale drawings in JPEG format to folks so they can compare whatever parts I make against their models, etc.