Sadly my fluffy, black girl, Colette, got lost in the months I was homeless. She would have been a good candidate for vanlife. She hated being outside so I would worry less about her escaping. She was clicker-trained and addicted to laser toys - 2 perfect tools that I cannot acclaim enough for leading a willful cat to where you need it to be!
Also, my brother’s cat will literally snuggle up to his space heater cranked up full blast. Cats evolved in a desert and allegedly prefer temperatures at least 10 degrees higher than humans, making them better candidates for vanlife than dogs. I was going to add that the bottom rear area of a van is the coolest part but the video covered that. I kept my drinking water there and it was always cool - even after parking the van all day in a lot in the summer. That’s good space to provide access to for your animals.
Scratching is an essential activity and therapeutic for cats. Do not declaw them. It’s cruel and painful. A lot of countries have outlawed declawing. It takes work but keep after them to use appropriate scratching posts. I used to keep Colette in my bedroom when I wasn’t home. When I’d come home and let her out into the rest of the house, I did everything I could (including demonstrating it myself lol) to get her to first scratch the post in the living room, work out that urge, and mark her territory. It helped significantly. My roommate bought anti-scratching spray to protect the sofa. That also helped but would have to reapplied daily and was hard for me to keep up with. Colette would have to scratch the sofa and “remind” before I’d reapply it. When the bottle was empty, I noted the scent-base (lemongrass), and bought a lemongrass Glade wax cone in a plastic shell for $1. I plunked it down on the floor where Colette was most tempted to scratch and never had a problem there again.
Regarding the vomiting, it would take some work (so does cleaning it up lol) but there’s always the option of experimenting with different types, brands, and flavors to reduce or eliminate the vomiting. I had a cat 20 years ago that I fed dry and she always seemed to throw up hairballs. I raised Colette from 9 weeks on a frozen raw diet as well as canned food. Neither hairballs nor profuse shedding were ever a problem, but she occasionally seemed to have reactions to the food.