I think what you are doing has potential 'problems', but you know
that. More support for that cable is certainly a good idea. The
'how' of it is one of those practical thingys, just depends on what's -
practical- for you.
I think you'll also find that RG-6 probably works okay on HF and VHF.
Get any higher in frequency and depending on the length of the run,
you can forget about using any of the 'common', non-hard line feed
lines. Get ready for that.
Either of the methods of supporting that feed line sounds like they'd
work. Pick whatever is easiest for you. And there ain't no 'perfect'
way of doing anything...
Paul