1) Please always remember that the 1st Amendment applies to the government, not to private entities--it does not protect you from actions by private associations.

2) Check you HOA agreement and any other policies affecting your residence in the community; make sure there's not some clause (which you'd agreed to, and hence could be enforced against you) enabling them to penalize you if you disturb the peace, violate certain standards for outdoor displays or signs, etc.

3) Under the law of defamation, you may make provably true statements, such as "the HOA charges $5,000/year in fees." You may also make statements that are clearly nothing but opinion: "I don't like my HOA." But if you make statements that have a factual component but which may be untrue, you could be sued for defamation. Saying something or someone is "corrupt" is more than an opinion--it implies that they took bribes, show favoritism, break the or bylaws, etc. It is a statement of fact, and if you can't back it up, could get you sued.