I think that weddings are always special times and honestly, the age of the participants has nothing to do with it. The people you’re inviting are your friends and family - how could they *not * think it’s a ***very ** * special day? 
Actually, she only deserves everything that goes with a happy marriage. That’s what it’s all about.
(Which you know, of course. I’m just gently teasing, in case it doesn’t come across well in text!)
Regarding the registry: well, as I see it, the purpose of wedding presents - and in particular, registries - is for young couples who are moving out of home for the first time and have nothing; it’s so they can start their new life with the things that make life easier - bed linens, crockery, cutlery, electrical goods, etc. It’s not so they can haul in the phat lewtz, although many brides and grooms seem to view it that way (I’m not referring to the OP here; this is purely generic stuff).
Then there are the people who think that because their wedding is costing X dollars, they have the right to ask for a certain $ value of presents. This isn’t so. If a person decides that the only way they’re going to be happy is to have a big wedding with all the frills, that’s their call, but it’s not up to the guests to subsidise the event. That’s a bit like buying a huge house and then charging admission to your friends to visit. (I’m sure the Analogy Police will write me up a ticket for that one…in which case I challenge them to find a better one!)
I’m not suggesting that people can’t give gifts if they want to - it’s a nice feeling when you give someone you care for a gift on their special day! - but registry cards make it seem like an obligation, and not everyone can afford the kind of things that tend to turn up on registry lists. If you put a selection of lower-cost things on there as well, that’s not so terrible. If you put only expensive things on there, you’re indicating there’s a ‘minimum spend’ before the person is good enough to attend your wedding, and that’s where I think it tends to go very bad very quickly.
But generally, I think asking for presents is just a bit ‘off’, regardless of how it’s done.
Whatever you decide to go with, you’ll obviously have put a lot of thought into it and that’s all that counts, really. I - and everyone here - can only give you our perspectives, but when you get down to it you are the only one who really knows your friends and family and what would work for them. (Maybe you should run these questions past some of them, informally?)
I do hope you have a wonderful wedding day, and that your marriage is a source of joy to you both.
Best of wishes. 
For what it’s worth, I specifically requested no gifts for my wedding, because I was 26 and had been living away from home for 5 years and had already sorted out everything I needed. My dad paid for the ‘reception’ though - he wanted to pay for some of the wedding costs and I knew it meant a lot to him, so I compromised on that. There’s a fine line between being independent, and giving people the feeling you’re telling them to (checks forum) er, ‘butt right out’ of things.