Love these ideas, Alone! However there are some issues as you know.
#1: As you've been informed, we cannot have the old music back into the game due to copyright. I too would love to see them make a comeback, but for now we don't expect to see them any time soon. For now though, you can go to the link AlphaEclipse had given you here (https://feral-heart.com/smf/index.php?topic=59827.msg912683#new) so you can still listen to them as you play. =)
*3/5/6: As Vortex said, we would need the source code to be able to implement them into the game. However, pets would be very fun to have. I can just see so many players running around with them. As for images, it would be very cool to be able to have a logo tethered to your group. I personally would love that. For the quests, that would add a very interesting element to FeralHeart. I'm not too sure on how I feel about it, but it's definitely something to think about.
#2/4: I personally would love to see another Ascension Island make it's way into FeralHeart. Looking to Eastern Pass, it has a smallish platforming area in it, but definitely not as hard or complex as Ascension was. It would be very nice to see a map dedicated to platforming like Ascension was. I've always thought about making one of my own, themed with very tall trees and branches alike--to which when reaching the top, you're met with a beautiful view above a forest. Perhaps the forest/jungle you were just in whilst traveling to the stairway of trees. I have a couple ideas of how it could work, though. For a recruitment exclusive map, I personally don't think it's necessary. Currently as you know, The Grounds is generally the place where various members like to collect and chat about many things. Hang out, do whatever. Coupled with that, due to group leaders looking for the most populated areas for the best chance of getting their group out there, they will go to those areas, i.e. The Grounds, to advertise their groups in hopes of gaining new members. It's self sufficient. The Grounds is where players will hang out, generally if they have nothing to do or just want to socialize, and groups go there to advertise because of that cluster players. As Vortex said for himself, you can just turn your Movie Clips off so they don't get in your way. Very helpful when Movie spam is high.
Once again, great ideas Alone! Thank you for sharing them~