Site search questions

[VisHorizons]

I've read this post, which gave me some good ideas:

I have a few additional questions:

1. If I set up a custom field for keywords, why would I choose multi-text (as suggested above) instead of text field? I did a little test, and I seem to get better results with text field.
2. In Search Settings, there's a checkbox labeled Use Database Full-Text Searching. What does that do? The reference guide says:

   Full-text searching uses MySQL FULLTEXT. This allows shoppers to search on any text string that appears on a product page. For example, a shopper might search on ‘twill’. If full-text search is enabled, all products with ‘twill’ in the description would appear in the search results.

   I don't know what MySQL FULLTEXT is. It sounds like it's describing a basic search function: search for 'keyword'; all items with 'keyword' will appear.
3. What determines the order of the search results, both on the results page as will as in the auto-suggest drop-down thingy? There's a particular item code that I search for, and the auto-suggest shows me the custom printed version before the stock version. This seems like a question I've had going back to my Miva 4 days, but... is there any way to sort these results?
4. Is there a (simple) way for me to see what terms users are entering into my site's search? Power Search had this feature and I miss it. That report would tell me the terms, date, IP address (handy for filtering out in-office searches), and how many results each query returned.

Edit: As always, thanks so much for any help with this.