John, I am beginning to wonder if the vent pipe is required. Without it the output would be a bit 'spluttery' but maybe thats OK.
I agree it is cumbersome in that the resevoir needs to be deep (at least I think it does) but I didnt have anything too fancy in mind, just 4" plastic drain pipe. Though I have shown nice straight pipe for the up tube of course just garden hose poked to the bottom of the resevoir would do just as well, it just needs a little fitting to somehow inject a bit of shop air at the bottom of the output tube.
I will be looking forward to your opinion on the mist modules.