1. Since GTA stole alot of stuff from elite, the new elite should steal stuff from GTA:Vice city: larger varity of ships, all areas to explore (planet surface + ocean exploration), pilot and ship seperation, first person exploration w/o ship).
Some of what you mention was available in the games Damocles (Mercenary II), and Mercenary III, which remain amongst my favourite games of all time.
However, I wouldn't want to see an Elite remake have any "on foot" exploration stuff. Leave that to the GTA's etc - Elite was always about space and spaceships.
I think landing on planets is a great thing, it gives the game a more immersive feel, but I don't want to actually get out and wander around. Plus Boiled Sweets would have a nightmare of a time supplying content for exploring individual planets! Put all that extra effort into providing more spaceship / upgrade variety, and a great trading system.