For the sake of having a "no, we shouldn't" answer for people to vote on.

Reasons for not following the Stack Exchange model.

1. A short greeting and thanks in advance doesn't add much clutter
2. This is a much smaller site than Stack Overflow, so friendliness and politeness should be encouraged to yo help foster a sense of community
3. Greeting and thanks make the site look more friendly, and so new members are less likely to be put off from posting

If anyone has other reasons, please feel free to edit them into this post.

For the sake of having a "no, we shouldn't" answer for people to vote on.

Reasons for not following the Stack Exchange model.

1. A short greeting and thanks in advance doesn't add much clutter
2. This is a much smaller site than Stack Overflow, so friendliness and politeness should be encouraged yo help foster within a sense of community
3. Greeting and thanks make the site look more friendly, and so new members are less likely to be put off from posting

If anyone has other reasons, please feel free to edit them into this post.