Seasons: They really carried the atmosphere the games. I really liked them
Pokemon Following You: YES. It's nice to actually see one of your PKMN traveling along side of you.
Concerts/Contests: Nope. They can get the boot.
Fog: In the Overworld, it can get the boot. But for VGC reasons, bring it back.
Trainer Customization: YES. Since I'm the hero, the hero should look like me. (Male characters need way more options)
Underground Mining: YES. The best way to get shards, stones, fossils, and those wonderful heart scales. Leave the secret bases above ground though
Secret Bases: Really time consuming and I had to quit like cold turkey. I'll take trainer customization over this though.
Re-Challenge Gyms Leaders: It's a nice way to train and you get to see their new teams they trained up.
Battle Frontier: YES. Pretty much killed ORAS in a sense. Delta Episode was cool, but you know what I really want.
Vs. Seeker: YES. There is honestly no need to get rid of this. With the mechanics of FRLG, no. But how in RSE you could check and see who would like to battle. PLEASE NO UNNECESSARY PHONE CALLS! (I'm talking to you Joey)