I am not saying what to do, just what needs to have something done.
Player bank/storage
To be fair, the dev team have done a ton of work on storage lately. The mount system was great. If anything, I'd love to see a cosmetic tab similar to the mount tab. Outside of that- as much shared storage as possible please!
Disagree. I love LGS crafting, cannith crafting, dread crafting, etc. Since they lowered the cost of cleaners, LGS is far more accessible than it used to be. And tier 1 + 2 crafting has always been low hanging fruit. I like diversity in DDO and wouldn't want to see the existing crafting options diminished.
Multiple player advancement mechanics vs one unified mechanic
Do you mean PLs, RXP, gear, etc? Character customization is one of the very best things about DDO. We can both play the same class and still wind up with very (VERY) different builds.
Lag (obvious but had to add for completeness)
Again, I think you're being unfair. It isn't perfect, but it has vastly improved over time.
This will always be an ongoing development issue. But- Steel started introducing smaller class tweaks (outside of comprehensive passes) which have been really great. And with Tonquin back in the mix it seems we are getting bug fixes and small incremental improvements by the bucketful.
silver/gold roll loot table
Agree a bit. Only because I'm greedy. Give me more shinies!
Join a guild! Post in any of the public discords when you play. Our guild is very active on Khyber most days from 8 PM - 11 PM and we raid every Weds and Sat. I know a few other guilds on Khyber who do the same.