I wouldn't say you're wrong, because we all have our own opinions and all that feel-good figgy-pudding jazz. But to answer your questions:
1) I feel they hold up fine. Putting aside that they're my favorite Riders (costume-wise and character-wise) I think they still work because they are what they are: the Riders from the 70's. Everything is of its time. It's like BLACK is from the 80's, and Kuuga is from 2000, and so on. That's when they were made, that's how they look. You can try to reinvent the wheel, but you got it right the first time anyway so why bother? Invent the hover-car instead.
What I mean is, when it comes to the "reimagined" suits, I think they're okay, but I still prefer the original versions to the revamped FIRST/NEXT ones. Aesthetically, the old ones are just more pleasing to my eyes, but they're also the ones that have become more timeless. When I think of Kamen Rider, I think of those first. When I look at THE FIRST Rider 1, I'm always going to think "yeah, that movie back in 2005." But classic Rider 1 keeps turning up and he keeps evolving in subtle ways. Those are the versions that made Kamen Rider what it is. Those are the ones everybody liked in the first place. The movie ones are okay, but they should be the exception, not the new rule.
I know some people grumbled during All Riders that they wanted all the old Riders remade revamp-style, but to me that's missing the point of bringing them back in the first place. The idea of having old stuff is to *have* the old stuff; this is part of why Decade proved to be so controversial. Some ask, what's the point of having Kuuga if it ain't Godai? Well what's the point of having Rider 1 if it ain't the Rider 1 I grew up on? Decade's Kuuga got away with it in the same way that THE FIRST/THE NEXT's Riders did: they're interesting cover versions, but that's it. Decade Kuuga existing does not suddenly erase all your Kuuga DVDs with Odagiri. And as nice as the revamped suits are, I'm glad that the team-up movies have the original versions.
I'd rather see new stuff like the TV Heisei Riders. They get pretty far out, but I like that more than just seeing the same stuff recycled and "updated" only to go out of style a few years later anyway. When you want to have the old guys back, have the old guys back, creaks and all. It should be the same way when old man OOO comes back for the 2071 reunion.
And I love the silver 'n red 'n stripes versions of the Double Riders. I said why enough in one of the other threads.
2) Nah.
3) Here's some Fandom 101: Generally, you will not convince someone the thing you like is good by bashing the thing they like.
Or to elaborate: Old stuff fans, you're not going to win the new people over with the old stuff if you tell them their Riders are all talentless pretty boys that have to rely on CGI for everything made solely to sell toys (Has anyone ever picked up one of those books on all the old Rider merchandise?)
Conversely, New stuff fans: you're not going to convince the old fans to even bother with giving the newer shows a chance if you say their stuff is all old, cheesy and fake and Tokusatsu is now soooooooooo much better, 100% realistic and not campy at all. As much as things have changed, the fundamentals are the same: it's guys in suits fake-fighting, with fake-looking effects. But who cares, right?
(I realize you can extend this to Tokusatsu as a whole, or even just for one show vs. the other. I'm using Riders as an example since I think Kamen Rider fandom can get a little too hung up on the old-vs-new thing sometimes.)
You don't have to watch everything, you don't have to like anything, but limiting yourself to one era is pretty dopey IMHO. Who cares when something was made? There's brilliant stuff in every decade, and there's plenty of junk in them all too. Some of the worst Tokusatsu I've ever seen came out in the 70's, my favorite decade of Tokusatsu. When it comes to the Riders, I think it has had a pretty high success rate across the board, and while my favorite shows happen to be older ones, it's not like the new ones are all godawful and must die. They've mostly been pretty good, to be brutally honest.
tl;dr: In an alternate universe somewhere, Barom fans are having this same conversation.