I am a jew by choice (i.e. conversion). Please do not feel that you need to convert with an Orthodox rabbi. Your conversion is a covenant between yourself and G-d and no one else. Once you convert, you are under the house of Avraham v'Sarah. This means you have the right to go to Y'israel as any...
The variety of answers here is not surprising; we are all at different levels of ascension based on our life paths and what life lessons we are to learn within this particular life time. This affects how we understand and perceive the coming of the messianic era.
The Torah does a good job of describing what is deemed defiled and by what ones becomes whole again. For example, the Torah speaks about Aaron's first two sons instantly killed for defiling the Tent of Meetings with offerings of alien incense. You can count leprosy, the wrong animal for burnt...