Regarding the space taken by the Member List, we currently have columns in ProSilver with mulitple items per column (Username/Rank, Website/Location), so maybe you could allow the admin to "stack" profile fields (which currently happens if somebody has both a Website and Location) in the ACP. For example, you could stack Username and Rank and possibly Joined and Last Active, or, if you wanted to show maybe birth date and gender, you could stack those with Username and Rank. That would allow fitting more items horizontally at the slight cost of making the column headers a bit more complex.
While this would obviously require a style change, it is not literally restyling the table. We're still using basically the same table and just allowing the admin more flexibility in how fields (standard and custom) are displayed. As such, it seems to fit here, not in some other RFC. As nadermann said earlier, they seem to be "strongly related, so only one RFC."
Steve