[_Drugz]

Well if you want something that could just loosen the curl pattern your best bet would be to get a texturizer, but do realize no matter what the chemicals could damage your hair. IMHO i don't like the way most texturized hair comes out, it just doesn't look good to me. (not putting anyone down who has one)
How damaging a relaxer is i guess is can depend on a lot of things..you really have to make sure you get someone who knows what they're doing when applying it or you could cause damage to the hair and scalp. There is also a matter of the strength of the relaxer and the chance of choosing one too strong for your hair. But remember no matter what, in a way you are damaging your hair from the use of harsh chemicals.
Will your hair be as thick? Who knows, some people i know have gotten relaxers and it made their hair pathetically thin, but others like myself still had thick hair. Although my natural hair gives my relaxed hair a run for it's money.

Basically, i just don't really care for relaxers and deciding to grow mine out was one of the best things i could have ever done for myself. I feel like you might miss your curls once their gone, you know how sometimes you don't appreciate things until you don't have them anymore. You may find you spend MORE time trying to get your relaxed hair to look how you want it.

Sorry for the long reply, this is just my two cents on the whole thing.