The first thing i thought of is the money problem because you
gotta pay for the house rent and not just food, transport, etc
anymore. But since you say (and certain) it's of no problem to you
at the moment, so yea, i say you're free to go to be independent,
learn and work outside.
It's actually not a bad thing. A child should go explore the
world him/herself and IF i do have one i'll let him/her go at 18.
And i dont regard movin out as abandoning your parents (drag too
far.... isn't it?) But one thing is, you GOTTA make sure you
have sufficient money to support yourself not just for 1 week, or
month, but probably long term.. depends on you.
18 sounds good and old enough to take care of oneself. But I'm
not sure of the legal issues though. You need to hit a specific age
to rent. Sorry cant be of much help here regarding the legal issues
but could only support your thoughts and i wish you all the best.

Is there no other ways besides movin out? No talk, mate?
(I guess your mind is set anyway....)