I use pine shavings in the rescue. It's cheaper. It never smells too strong, and if it does I just air it out.
Be easy on the veggies if they don't usually get them. You don't want to cause digestion issues.
It's great that you are trying to help these pigs out!
We have a really large rubbermaid tub that we dump our shavings into for storage, so it has plenty of space to air out.
About the seed based food--I imagine a lot gets wasted, so it actually costs more in the long run than good quality plain pellets!
As for the pellets, that's what I thought! When they arrived at my house the pellets were everywhere and the bowls where filled with poop, but that could have also been from the stress of riding in the car for the first time ever. She gives them as much as they want too which I imagine is way worse than buying hay (a large bale can be less than $7) and a couple of veggies each week.