(1) Sounds like a decent idea to try.
(2) Never going to happen. If a hog can get his nose between it, he will work his way through. I've seen wild hogs go through hog panel with heads that appeared bigger than the hole they went through.
I would run 2 strands of barbed wire on the outside of your field fence. Bottom strand on the ground tight, 2nd strand 6"-10" above that. 3" barbed wire, barbs 3" apart, would be best. Cost wise, try to re-use what you already have.
