The last release (1.5.7) have a nice tool that locks lines on three major axis (OX, OY and OZ) that can be enabled/disabled (named Ortho tool). At the end I hope that you will feel more at home with free angles.
Look how it works in this small video. If you want to test it, pick the nightly build from right:
Note, if you will want to test the new spline code, this code is fairly broken.