Yeah, unless you "lose your membership"...I knew some people that lost their membership...somehow...
Yes, when you're one month (or how long you payed for) period is up, you lose that membership.
I know...but at 6 bucks (US) or whatever currency... why?
What level are you in RS Omega? Members have a great advantage over F2P People...besides poison and other stuff...
You can look up "hofmic" to see for yourself. Recently got my farm over 30 (currently 48, but should be my target of 49 by tonight), so I'm ranked in everything.
And yeah, members have massive advantages. Soul Wars, the abyssal whip, hunter, slayer, improved all skills, better dungeoneering xp if over level 90 combat, dragon equipment, uber awesome quests, bigger world, fairy rings, more monsters, summoning (mixed emotions there...), among others.
Poisoning's not bad too, but it's a double edged sword. Not only can we poison, but we can be poisoned! I rarely poison though, other than some bosses with a DDS special or perhaps the dragon spear (kp).