No. Even if you have 99k to pay for it and a skill that you have level 99 in, you cannot purchase or wear a skill cape unless you are a paying member. I'm sorry... I wish we could, too.
Yes, you have to be a member to obtain ANY skill capes in Runescape. Skill capes were intended to be made for recognizing members who reached level 99 in a skill, not really for non-members. Although, a common trick to obtain the skill cape while not cracking your budget, is to get a 1 month subscription to runescape, buy the skill cape, equip it to your character, and never take it off again. If you take it off, you can't put it back on once your membership is depleted. Although, this was a relatively old trick and I do not know if this still works.
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.
Then the same thing will happen, you will still get trimmed capes.
Yes, you can do a runescape skill cape emote on a non members world even though the cape itself it a members only item, you can still do the emote as long as your wearing the cape.
Yes? You still can use the skill, even if it is at level 99, the level cap for Runescape, except Dungeoneering.
No. There are certain free skills (example: woodcutting) in which the master is still in the free-play area (the master north of falador) but there are some free skills (example: firemaking) in which the master of the skill is not in the free-play area (the master south of seers village.) Also, a "small" fee may be charged when you buy the skillcape. I.E. the mining skillcape costs 99,000 gp. Yes, you need to be a member to get any and all skillcapes.
No, skillcapes are a members-only feature! You can simply get 99 in a skill then purchase a one month membership to buy the skillcape. When your membership expires leave your skillcape on your back and you will still be able to wear it and do the emote in non-member worlds. If you take the skillcape off in a non-member world the only way to wear it again is to buy another membership.
Then you can't get a skillcape. But you can still boast of having the skill - to substantiate this, you can either say it in quick chat (since the skill level is filled out by the system, so you can't just invent a skill level), or refer people to the hiscores
It already started. Members who registered can try out the beta at any time; members who didn't register can still try it out on weekends.
No, the only way that you can but still involves payment from a friend, is if a friend gave membership to you as a gift.
Of course it will appear next to you when you log into a members world, or if you stored it in your bank, it will still be there when you log back in, no worries.
You buy a membership and then buy members things. Members things can't be used on frree worlds you can wield on member worlds and swap, you will still be weilding it but the stats will be the same as nothing.