@Lisa M I hear you but when updating, one needs to also consider if there is any true architectural significance to what you are changing. Plus one needs to consider if the original was actually done well or was it just done to the trends of the time? Is preserving trends of the time of architectural value? Maybe. But we live in the real world with budgets, labor/material availability and new concerns impacting our decisions. Horizontal siding application requires expertise to avoid the risk of water leakage around windows, doors and other openings. Water finds its way and when it does it's damaging and can have adverse health impacts. Accommodating the horizontal cuts results in a lot more wasted material. So does today's enlightened awareness of sustainability and reducing waste secure a higher place on the priority list than preserving a look that recalls the trends of the 70's? Not sure if you are working with outside tradespeople on your shed, but finding quality craftspeople to do specialized work well is a lesson in patience, often literally years out, in my very active region. Specialized labor plus more material equals more cost. What are the family's other budget priorities? Does preserving a 70's trend outweigh saving for a child's education or your own retirement? To answer your question: "why would you buy a very specific 1980 house and try to use it as a springboard to faking the look of new build houses on your inspa lists." In the current real estate market, most folks buy a house based on location, cost and the ability to actually get your hands on a house in this crazy bidding market. The house style often has little to do with the purchase decision. May I point out that the OP has two, not four or five different siding styles on her home. Even FLW used two siding types on his own Oak Park house. If it's good enough for ole Frankie, I'll take it! Could he have bricked the entire house? Yes, so is that shake siding an arbitrary decoration? Who's to say what's an arbitrary decision on any structure? Some thought went into everything chosen. Not everything is precious on/in houses of their time. I just gutted a classic harvest gold bathroom. Should I have replaced it with the same since it is of the times of the house? No thank you. It had a good run and kuddos to the tile craftsperson who installed a shower pan that lasted 53 years. And BTW, thank ya Jesus for "James" Hardie. Had the company he established not pioneered fiber cement products, we'd have a lot more asbestos, rotting wood, black mold and ear piercing wood peckers waking us up at dawn. Big questions are interesting to ponder. Just not sure making assumptions about a poster on Houzz and the decisions they made is the place for it. Probably better to post your big questions as your own posts for comment. But...that's my opinion.

Real wood should not be a problem in a moist climate, if it is the right wood with the right treatment. You're not going to get any non-wood product that looks like wood.

Check HD for lights https://www.homedepot.com/p/Maxax-Montpelier-12-3-in-H-Sand-Black-Dusk-to-Dawn-Outdoor-Hardwired-wall-Rectangular-Scone-with-No-Bulb-Included-MX7005-W1BK/323998485

I’d keep it more uniform. Either all iron ore. Or all green. I like the idea of removing the shutters completely , but I don’t know if they are stained or “sun tanned” beneath. I like the sound of a new door. Did you pick one out yet? Maybe choosing one without a sidelight but with windows in the door itself. For a more grandiose type look… I’d also put focus on landscaping especially the border for the garden beds…