We are doing a 5 night, will I feel overwhelmed trying to do it all in 5 nights?
If you try to "do it all" in five nights, you will be exhausted, overwhelmed and still won't be able to do it all. There's a lot going on all around the ship from casual encounters of characters to scheduled activities to musical interludes/performers both in lounges and on deck, movies, shows, shopping, swimming, spa, alcohol tastings, cooking demos, trivia, ship exploring by yourself or with tours..... You may not even be interested in all of the activities. And then there's relaxing by the pool, in a lounge or cafe, on deck, in your room, not to mention eating.
My suggestion: spend the first day or so just wandering about the ship and exploring (there is usually 1-2 tours on the first day - listed in the Navigator - I highly recommend it). Then pick some things to do that you really want to. Don't forget to add in time for lounging, relaxing and staring at the water. Go to the shows. Maybe a movie or two (either first run movies in the theatre or older ones on deck). After 10 cruises, we still feel like we haven't done everything plus there's always new stuff. Sometimes we end up spending a sea day doing little more than moving from lounge to cafe to pool to room to lunch to lounge to deck. I often joke with people that I have no idea what I did on my sea day but whatever I did it took all day. Some of the lounges are so lovely that we just want to spend some time in them and see what they're like (and if we have a drink or snack there, well, it's time well spent IMO).
I read that you have to dress up for the adult only restaurants. My husband does not dress up, has nothing but jeans and shorts and t-shirts. Nothing with a collar even. That was the main reason I decided not to eat there. Just didn't seem worth it to buy him something he will never wear again just to eat there. But if it's truely life changing it's so good then maybe buying dressy clothes would be worth a meal there lol. We are cruising on the magic.
I don't know if I'd call them life changing. We enjoy it but we also enjoy dressing up and spending several hours at a multi-course gourmet restaurant - that's as much a part of the vacation as anything else to us. Not only would I say that perhaps it might not be your thing based on your comments, but I actually don't recommend doing it the first cruise, especially a 5-day one. We did Palo on our first 4-day cruise and while it was very nice, I almost wish we hadn't. We missed the one night dining in Triton's on the Wonder and we've never sailed her since so I never got a chance to really see it. Since everything will be so new to you, I say stick with the main restaurants so you get a chance to see them all and all of the menus (no two nights are the same). If you really want to try Palo's, try the brunch if they do one as it's more casual and doesn't interfere with going to the main dining rooms (although it may interfere with your appetite for dinner!).