There are a lot of truths in the things you've put in this thread, but there are also other things to be considered. I've been in and out of the server for a very long time, and I've seen wave after wave of new players. The truth of the matter is that yes, old players get bored of the mechanics in the server and quit. Most veteran players don't play the server for the actual server mechanics, but to interact with the garnet community. I couldn't tell you the amount of times I've logged on, checked leaderboard, saw nobody I liked, and got off. The memories I've made in the server don't really consist of farming in my base, but doing stupid shit with other people on the server.
Alting does not inherently negatively effect the economy. The players who are getting the printers and farming them are really in control of the economy. If those players are buying crates, interacting with gun dealers, hiring hitmen, or any other roleplay scenario that can spread the wealth; then there is no issue. Even if those players are selling the money they gain for credits, the economy is working as intended. The only time that alting becomes an issue is when the pop is 110+ players. It's always been a hidden rule that the SA of the server would kick off any alts that were taking up a space that a real player could.
I've spent years watching the economy of the server, because I've always been extremely invested in it when I play. It always bounces back unless there is power being abused(Rohan). I've been through at minimum 2 econ wipes, maybe even 3. I can guarantee you that the alting does not correlate to any econ wipes.
Now time to talk about additions to the server.
I'd enjoy seeing additional crates in !unbox. (Add spiderman swep or some shit to a crate, add emote sweps, add drug crate)
A different gambling addon. I'm not sure if this ruins any "vanilla" aspect, but I'm sure community would like it.
Change prices of trails and materials for prestige players.
Skill trees? Now this is definitely a stretch on the vanilla idea. However, adding skill trees is something I have always dreamed of for this server. Im not sure what the categories would be and their benefits, but I really like the idea.
Implemented clan/gang/crew/etc addon. I'd like to see more than just /party to play with friends. I'd like to check stats of a clan and see how many people they have, their clan level, etc. This would be great for immersion and increasing the quality of community in the server.
TLDR : Most vets play for community not game mechanics. Alting doesn't ruin econ, I saw with my own eyes! Green is additions to server