Mmmmm - I'm not too sure about one or two of your answers there windswept...
Firstly, some operators need CAS to ensure that their ac are correctly insured...
Secondly, there are gaps now in the LARS, so would it be ideal to plan on unit to unit? Last thing you need is flying in an area of reduced radar coverage from below/side because you're operating on the limits of someones radar cover and something happens. see answer above.
Thirdly, You're comment about Euro-Control. personally, I take pride in making sure ALL my routes CFMU compliant, rather than just chuck any old rubbish into the system and make it someone else's problem...... PPPPPP (and not very professional either). Last thing you need to be doing is peeing off Brussels/Paris just because you're too bone idle to correctly route plan. I've seen it before, a short notice trip, chuck something into the system , hoping they'll give you an ACK and you get a REJ. Who's got egg on their face now?