SWG and EVE are closer to sandbox or open concept in my eyes. They offered more freeform style in what you could do. Both offered more to do than just lvling. You could do questing or just sit and chat but still gain some progress with a ton more automation and offline progression. Automation is lacking in many other games. Those that have the open idea to allow hardcore gamers and the odd 1 hour a week or 10min a day player options to have something to do can and will pull in more players. You see that a lot with Eve.
Big thing that SWG suffered was the lack of timely content releases. They were playing the dog catching its tail till it was trashed with NGE.
SWG had non-hardcoded classes, meaning you could grind up a class or multiclass with options on what points to assign to which classes and a point limit to keep players from grinding and keeping all classes maxed. With that you could clear out all points and become a noob, no-class and grind up as something new again.
http://www.swgcharacterbuilder.com/swg-cb.php
It had open areas to allow players to drop a house anywhere then later Player Cities and themeparks relating to the movies to get items "Trophies". You couldn't really buy or sell items to NPC vendors. It was a player driven economy. The thing to note, you could only have 1 toon per server per account. If you wanted another toon on the same server you had to have another account.
Later they added in mounts (pets/creatures) then mechanical mounts. I think Towns hit then space and later NGE that really killed the game forcing player to be hardcoded as a class with no option to change.
The best thing from SWG was the crafting and dynamic quality of the mats. When you harvested ore/materials it had quality level. You could scan the area to get the best concentration (Think Eve-PI). Once you sample the spot to see the stats, you would decide if you wanted to continue or move off to another spot in hopes to get better mat quality.
The mats (ore/materials/etc) had stats to it, things made from this stuff helped to change the finished item. So then you have 100 gunsmiths making 100 of the same gun, the mats they used would give that gun different stats. Some would hit like a MAC truck, others had a distance so far you could hit another solar system! Others were a mix of crap that didnt hit from much and was lucky to get the round out of the barrel.
SWG lesson for those that didnt know the game or a kindly refresher for those that did.
Not sure if I would pull in the class point system but the craft would be nice to have in all games! I know both games are Sci-fi but the ideas and gameplay could be applied to any game. Hell, even the new SW game TOR has some good ideas. Companions. This is a great idea but needs to be tweeked better and more dynamic.
I think it would be nice to pickup and trade NPCs you have for your house or the guild hall or the town you are apart by giving giving them orders. Fix the wall, train some soldier, patrol the boarder, craft some armor, dig a mine..etc..etc. But NPC you could find, quest for and trade but also skill up (STO officers) and focus a master skill and then limit the amount of npcs a player can own by faction level, housing size, guild rank and town status.
The biggest thing I thought should be in EQ are more NPCs doing stuff. Not just standing there or moving in a circle but actually doing something. Like you as a player buy all the rubies from X merchant and a banker or the npc's kid, wife or co-worker goes to the bank to get coin and/or hits the jeweler shop to get more rubies and comes back. With that idea a player could if wanted, kill the delivery NPC and get the restock items. Bounty would get placed on the player if caught, posters would start being put up from NPCs and later any NPC within X range from a wanted poster would attack the player and remove X amount worth of coin the bounty was worth. Just an example but doable.