As a typically staunch promoter / defender of Cinema's modelling toolset I still can't argue with your criticisms of those 2 aspects of it. There is certainly much to be done by way of improving both Line Cut and Poly Pen, particularly relating to their behaviour around ngons. But me and a fair few other modelling-focused testers have good coms with Maxon and ensure they are fully aware of our frustrations, and we do constantly push for improvements and fixes to the modelling tool set. And Maxon do listen to those concerns, fix what they can as they go along, and bank up ideas and retooling plans for the next time modelling is in 'dev-focus' so to speak...
At the moment, unsurprisingly, it's Particles and Liquids that are getting a lot of focus, but it'll be modelling's turn again soon enough I imagine...
CBR