In runescape can non members sell members items?

Answer 1

No. In free worlds, members items cannot be used in any way, nor can they be sold. Your only options are to keep the items, or to drop them in order to get rid of them until you are able to sell them via the Grand Exchange.

You shouldn't need to worry however, since members items occupy members' bank spaces and do not affect your free bank spaces.

Answer 2

No you cannot. Member Items become completely worthless and untradable on a Free to Play World. For you to Trade/sell or buy a members item you must become a member of Runescape.

Answer 3

Wield (in a member's world, and keep wielding while in f2p. You cannot start wielding it in f2p), drop (some might have special effects, eg.: ectophial, god capes), examine (every member's item has the same examine phrase in f2p) or deposit in the bank (provided you have enough space for it. Some items cannot be deposited, though, like the lamps from A Small Favour quest). The use option is useless, since the member's items are unusable in f2p.

There are, nevertheless, a few items obtained in member's worlds which can be used in f2p, like Maple Logs.