|Amy - great questions!
I hope I can answer at least some of them and give you references to other pages online. There is so much information and misinformation that its hard to know what to do.
I'll start off with the easy ones. Yes - if a tool is in contact with the urushiol oil then another person can get a reaction from coming in contact with the oil on the tool. Urushiol oil is a secondary chemical found in the leaves (not on but in canals within the leaf), vine, and roots of poison ivy and poison oak plants. Urushiol oil is fairly stable and can last for a period of time under the right conditions (dry climate from what I've read). So, if you get urushiol on the gloves say from pulling vines and then handle the loppers, yes you can transfer the oil to the loppers and leave a nice little surprise for the next person. You mention a pond - is that on the property? Could you just at least dunk the tools to help remove the oil?
Before I forget to answer the question - yes, once your gloves are in contact with urushiol oil they are now "contaminated". I use my gloves (those long rubber ones) only for pulling poison ivy. I have another set I use for other gardening tasks. Perhaps you could keep handy another set of gloves for general work.
As for your pets - yes if they wander through a patch and end up with urushiol oil on the fur, you certainly can get a rash if allergic. I've had many such occurances with my dog. Having your dogs roll around in the grass and taking a dip in the pond should help remove the oil. I was just reading a report from a somewhat noted dermatologist that he believes that just a wash with water will not remove the oil. But I've also read to the contrary. We have our dog take a swim in the pool after he's been in a poison ivy patch. We haven't had an incidence of coming in contact with urushiol oil due to the dog since starting this. It could be that the chlorine in the water acts as a solvent to help remove the oil. If so, you could wipe the dogs down with an alcohol wipe and send them in the pond.
As for the alcohol wipes, the issue is that you need to get the urushiol oil off. I have used wipes in a pinch. I'm very careful to use one that is very wet and don't wipe anymore than I necessary. That seems to work. True story: I decided to take some pictures of spring poison ivy growth. I had a sheet and box I was using as props and background when needed. The box came in contact with the leaves and vines of new growth often. This went on for 3 days (lousy weather made for so-so shots). Each day, I came in and used wipes on the box, tossed the sheet in the washer, and washed my hands. I am allergic to urushiol just like the rash and yet I didn't break out this time. I think the wipes work ok in a pinch. You could carry an old milk jug of water to the property along with some soap or solvent (see the How Soap Works page for more info) like Tecnu, alcohol wipes, Dawn dishwashing liquid, etc. Solvents and soaps work to break up or remove the oil. The water helps to wash that all away.
I understand that water will be at a premium but perhaps there is a way to at least have some handy. Doesn't have to be nice clean tap water - just something that will take the soap, solvent, oil away.
As for hubby - tell him to stress less. Yes he can bring on hives by stressing. Check out this link, Stress and Skin. I can give you many more references on this if you like. Also, tell him to curtail any scratching as that too can cause histamines to be release to the skin and voila! more rash.
Good luck on the project - it sounds wonderful!