I have one of those 3 X 5 flags on a four foot metal rod mounted into a bracket on our fence by the highway. It is secured to the pole with two plastic ties. I was able to slide it to "half mast" and it makes a very powerful statement. After the funeral on Friday, I may put it back to full mast for a day or so, and then bring it in.
Sounds great. You've got it covered except for land it is Half Staff and for sea it is Half Mast.
By the way after reading the other day about a Freeper calling businesses about their flags not being flown at half staff, my husband took note while out and stopped into a MAJOR business to ask about the flag. They had to end up taking theirs down completely because the way the pole was configured they could not fly it at half staff. At least they took it down rather than be inappropriate and that's why I would not name them. They weren't being disrespectful, in fact they were shocked they themselves had not thought about it. We appreciated that. Would be nice if they had your configuration. :)