Greetings, drunk bearded man with a red pointy hat, stuck at the bottom of the garden under the rosebush!
Welcome to our forum.
To answer a few of your questions...
The skeleton pocketwatch is REALLY a modern thing. To find a vintage skeleton watch (they were called "salesman's watches") is pretty hard.
Keep in mind that these days, pocketwatches are NOT TIMEPIECES. THEY ARE SHOWPIECES. They're designed to be seen, shown off, look pretty and cute...but keep time? I wouldn't trust them so much. Why do you think they have skeleton watches? To show off.
You have to understand: Pocketwatches MADE today are designed to be showpieces. Whether or not they actually KEEP TIME is irrelevant. They're mostly cheap showthings.
Vintage watches were made to keep time reliably because that was all you had to use, and so it had to WORK properly.
That's not to say that all modern watches are junk, or that all vintage/antique watches are amazing. It's just a general view, but it's something to keep in mind.
Let's say you pay X dollars/pounds/Aztec cocoa-beans for a watch. What are you buying?
Modern watches are showpieces for the most part. But that doesn't mean they're junk. For enough money, you can buy a modern pocketwatch that keeps great time. But most of the modern watches you find, are gonna be the cheap-to-midrange things. Gold-plated trinkets. Which is fine, if you ignore the fact that gold-plating will barely last six months if you use the watch regularly. Just as then, and now, quality costs money. Companies like Breuget, Tissot and Patek Philippe DO produce beautiful mechanical pocketwatches, but they cost in the thousands of dollars. What you're after, is likely to be the cheaper, gold-plated things. They might keep good time, but the quality on the case, on the crystal, on most other things, won't be there. Sooner or later, the gold will wear off, or the silver will wear off, or the nickel will wear off. The only way you could prevent this is to handle the watch with skills of an advanced telepathist.
A vintage watch that you're buying will have the money going into a decent gold-filled case. Gold-filling takes a long time to wear away. I have a cheap gold-filled case that's 110 years old, it looks brand new. The money spent on a vintage watch of assured quality will go towards something that was quality-tested and machined to keep the best possible time of its day. Why? Because back then, such things mattered, just as they don't matter with modern pocketwatches, because not as many people rely on them to keep accurate time.
If you WANT a hunter-case watch with a skeletonised case with a good movement that will keep good time...Yeah you can buy one. Hell, I could even FIND you one on eBay right now. But you have to understand that these days, things aren't made to last like they were back then. It might look pretty for a few months, but if it's a gold watch, the gold won't last like on a vintage watch. The cases aren't made the same way as vintage cases. They don't have the same tightness of machining and so-forth.
It's a trade-off.
Modern is easier to find, generally cheaper, but there are more quality issues.
Vintage may be harder to find, more expensive, but the fact that the watch has lasted 60, 70, 80, 100, 120, 130 years...is a testament to its quality and longevity.