Welcome to Inkscape Community!
Sorry it took so long to get your messages posted. But I see it didn't stop you from troubleshooting
I'm not a technical illustrator, but I am also from the "BC" generation where I learned how to draw on paper, and computers were considered science fiction!
I don't quite understand "ellipse templates placed at points on a thrust line....". Of course you've found the Ellipse tool, and at least some of its features. Inkscape also has axonomic/isometric grids! So you may be able to do a lot on your own.
I'm sure there are plenty of Inkscape users who are technical illustrators! Plenty! If you're wishing to be contacted by them, you might want to say a little bit about why. Otherwise, I guess you would just browse through the forum and essentially guess what they do by the questions they ask (or how they answer).
Is this the kind of technical illustration (2 image on this page)
http://inkscapecommunity.com/ic_gallery/thumbnails.php?album=47 ? Or do you mean more like blueprints or engineering plans?
And of course you're familiar with CAD type of software. Sometimes people are so impressed with what Inkscape can do, they become disappointed that it doesn't behave like CAD programs. But Inkscape is truly capable of precise drawing.