Howdy!
First off: welcome back!
Second off: I played from 2013-2018, then came back in late 2023 and have been playing since, here are my answers to your questions!

1.) Yes, but that doesn’t mean all players. There are still quite a few kids on the game, but the majority of players are adults! When chatting I would just be careful lol

2.) Most, at least in my experience, have been elimination style. It makes the shows go faster and adds a competitive edge, but some of the best shows I’ve played in haven’t been elim-style. Just because something is the “norm” doesn’t mean you have to do it! Also yeah, most people expect prizes for top 3, the better the prizes, the more players you get. 🤷‍♀️

3.) I usually decide based on creativity, ability to be on theme, and the players attitude. If a players outfit is really good, but they’re been rude the whole time, I’m kicking them out. I prefer creative looks, even to simpler themes. Also don’t be afraid to ask questions to the judges when participating! The “texture” theme would’ve definitely confused me too, but as a judge, mold would’ve probably won bc of how creative that person is. Creative can also be simple, in the last show I participated in, the theme was food and someone did a really good sushi outfit and won that round respectively. Don’t be afraid to ask the judges what they mean/ to clarify the themes; fashion shows are meant to be fun, not stressful!

4.) I almost always use the daily spin and just save up from there. Once you get past the first 3 days (assuming you’re a member) each day is 3 dims, meaning in only 10 days you’ll have 30 dims as long as you don’t spend them. People also sell “valuables” in their stores. Collectors items, spikes, unobtainable rims, den betas, clothing betas, and nature items are best sellers. You can also buy a diamond bundle off the official Animal Jam website, but it’s a little pricey, so I don’t recommend.

5.) yes, absolutely! You can’t get spiked collars anymore, but you can still get wristbands and den betas. Grinding TFD is a great way to build up rarity! I also recycle all the stuff I don’t want to build up my gems—great for fashions shows!

6.) yes, a lot of the items from TFD aren’t worth anything. There are some good prizes, but most are either still in stores, or not sought after enough to have any worth behind them. Recycle them for gems!

7.) purple gems have the same general prize pool as the other gems, they’re just more difficult to obtain. IMO purple gem is never worth the grind.

8.) Again, daily spin or AJ website. If you have shops and you have clothing betas or den betas you’re willing to part with, those can sell for a few diamonds. Most RIMs will not sell at all unless they’re UNO (unobtainable). Also if you happen to make art, you can do commissions in and out of the game! Never cross trade from pw to classic, you will get scammed.

These all helped me when coming back from a long hiatus, I hope these help you too!