you can keep all your items but you can't use them in F2P.
You can merch items.
Trading in F2P is simply exchanging items if that is what you are asking however th term "trade F2p" is something i have never heard of and i have played 3 yrs...
Yes he can but he but he won't be able to trade them while he is still a f2p.
The only Guthix items in RuneScape f2p is the Guthix rune armour. The only way you could get these items for free are via gift, drop party, or player killing.
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.
No, that is only for members. However, F2P players can BUY certain items from treasure trails - for example, Saradomin armour, or gold-trimmed armour.
Yes. As seen with several P2P players that go to, say, F2P Clan Wars, they retain their members skill capes, and they can still even do the emote for their members skill capes. Also, you can wear any members items in F2P worlds, although you do not get any bonuses from them. Once you take them off, too, then you cannot put them back on unless you go back to a P2P world.
Nope :)
The only f2p dragon is the one from the quest "dragon slayer".
There are no free-to-play poisoned weapons in Runescape, no.
I think runescape is
Gravite shortbow.