So my wife, against what I suggested, bought some Salomon Vigil boots before really trying on everything out there. She's not like me, where I would spend weeks trying on boots, researching, etc before I commit. My problem is the boots don't have a dual zone system, so you can't set up the lower and upper tightness separately, so I'm not sure how to solve her problems:
1. Her feet are slightly different sizes
2. She has circulation problems
3. When riding last week (her first time this season) she said her heels were pulling up badly
What can be done to remedy this problem? I suggested she wear a thinner sock on her larger foot and a thicker one on her smaller foot to help with spacing and circulation. She thinks heel cups will help with the lifting. Would heat molding her boots help? Any other suggestions?
The socks thing might help, but probably not to any significant degree. There are J-shaped pads that might have come with the boot that you can insert around the ankle to keep things tight. If they're heat-moldable liners, molding them will definitely help. You can also just tighten the living shit out of her boots too, but that probably won't help the circulation thing.
Although my first piece of advice would be to return them, take her to a ski store, and try on a few pairs (months and weeks of research is going overboard, but going in blind and ignorant is no better). If their prices are outlandish, just try them on, make anote of which she liked more, and then buy them online.
However, I would suggest you support the local business even if their prices are a bit higher. One day you'll need an emergency piece of gear and if they go out of business because everyone shopped online, you'll be shit out of luck.
On another note: you, your wife, and snowboarding. I have experience in this area. She jumped the starting gun and ordered boots. Don't get down on her for this. She's obviously very excited to get out on the slopes. Foster this and you'll have a snowboard buddy for life. I don't know how experienced she is, but a private lesson is also money well spent. Have patience and don't yell at her. I've seen guys literally call their girls some pretty derogatory things on the slopes while trying to teach them to board, because they're losing patience. That's not how you teach someone to board. Patience, politeness, respect, compassion, and understanding should be your mantra here. It's worth every second of your time once she starts joining you on the slopes.