Hello Lalawson
Back to your inquiry about lightening that dark wood. Whitewashing is usually reserved for unfinished wood- as it's purpose is to allow the grain to show through and create an interesting effect while persevering the wood. I love the whitewash finish I have seen in RV remodels. To look good, you would need to remove a lot of the finish that is on the cabinets now, either by chemically stripping them or sanding the H* out of them. Take it from wood restoration experience here, neither of these operations are fun, they are labor and time intensive, and make a real mess. I totally dislike paint on wood, and have stripped and restored furniture for over 40 years to get back that nice patina. It kills me to think that when I buy a new TT I may likely have to resort to putting paint ON the wood cabinets and trim. But, in considering my options, I think painting ugly dark cabinets to lighten them is the only viable option-unless I pay someone else to strip/sand them (not likely).
Also, I've learned that sometimes the sides or trim on cabinets are actually a wood-looking vinyl or plastic like paper that would not take sanding. They can take paint however. Don't know your particulars of course.
My 2 pennies, redo and remodel your new TT to your heart's content. Forget the resale potential and enjoy your home. I for one don't see my TT as an investment and I don't need for it to be in order to justify owning one. Although there is a constant theme here about resale value and how much Mr. X sold his old one for, I'm not swayed by it as a major concern. Markets for every used item out there -whether trailers, diamonds, or Beanie Babies - come and go and predictions about those markets are completely uncertain. If someone down the road doesn't like my painted cabinets, then they can offer a lower price and I'd be fine with that because I would have loved living in my abode and that's just part of the price I pay for doing so. But, that's my take based on my life stage, others may have different priorities based on their circumstances.
Go for it! I'm jealous of your confidence and ability to do the upholstery as I've not learned that. The window trims I can probably handle.
Google "RV remodeling" or "renovation" and be prepared to see some awesome stuff. Linda