"Is this 6' fence (see picture) a sufficient trellis for the beans? "

That's the height I use.

"Do I need to run some twine from top of fence to where the beans are planted to provide further support?"

The beans will twine around the fence verticals just fine. The only issue I see is that possibly the verticals are too smooth, but I doubt it. If you see the beans are slipping down, you can wind some twine around the verticals.

"Will planting beans on the fence corrode the fence?"

Dampness will be retained longer than it is on a bare fence. Whether that will cause corrosion depends on a lot of things.

"I've OKed the pole bean planting with neighbor already, but out of courtesy, would rather keep as much of the beans as possible on my side so I don't have to go into their yard to pick. How do I achieve this?"

You can't. Beans will grow on both sides. Invite your neighbor to pick beans from his side.

"Will the pole beans growing on my fence look unruly (I'm going for a green screen look)? Do I need to prune the vine tops when they reach the height of the fence so the vines don't start flopping in air? Will topping off decrease the harvest?"

I let mine flop. I believe you could prune without losing much. Wait and see how they look. Maybe you won't mind the flopping.

"Also, I've read about nylon netting for trellising. I'm more interested in twine b/c at the end of the season, supposedly I can compost the dried up vines and twine together, so less hassle. But what are the pros/cons of nylon v. twine?"

I use twine strung from a wood framework. I don't have a fence. I don't think you will need netting or strings.

Jim

Jim, thank you so much for your advice! How far away from the base of the fence should I plant the seeds?

I'm not Jim, but I can help you here. Plant them 1-2 inches from the fence. I like to plant mine right under the trellis if possible -- they'll grab on without too much help from me then. But since you're being considerate of your neighbor, you might want to make sure you plant them obviously inside your property line so there's no trouble when your neighbor wants to mow right up next to the fence on his side. If any of the vines want to wander across your yard, you can gently move them back into the fence area until they catch on.

Don't prune the vine tips, that's where the new blooms will be.

" I'm not Jim, but I can help you here."

You did a fine job, Anney.

gardenerzone4, you will not only be considerate of your neighbor, but considerate of yourself as by planting where the vines will be out of danger from your neighbor's yard work. More than once people on GW have posted sad stories about crops along a property line getting mowed down by a neighbor.

Jim