I had a plumber install an out door faucet, but he just installed a sillcock, not a frost free or type that can be shut off and drained. It is in a crawl space. I live in Michigan where the winters freeze. He said it wouldn't freeze and that the frost free type freeze more. I don't want to have a surprise this winter and flood my crawl space. I asked a plumber at the local hardware and he also said it wouldn't freeze. Others said it would freeze for sure... what should I do?

Where you paying him ? If so he is to install any type you tell him to, that is my biggest issue. Next I would have demanded a warranty and statement in writing, that it would not freeze.

If the crawl space is not heated the sillcock will freeze. In most states where the temperatures are freezing and below in winter, frost free sillcocks with vaucuum breakers are required. I have only known them to freeze when you leave a hose connected to them all winter. My other question is what is to prevent the water line going to the sillcock in the crawl space from freezing? Depending on how cold the crawl space gets insulating the water line will not always keep it from freezing. A solution would be put a valve with a drain cock outside the crawl space and shut it off and drain the line in the winter.

I shut off the water to my outside valves and leave them open, the way people did before the freezeless ones were invented.
Of course it needs it's own inside valve to shut off.
I'm too cheap to install the expensive ones.
You just have to remember to do it each fall.
I agree that someone you hire shouldn't be telling you what to do, unless you got the quote without discussing the more expensive option.

I agree with Puff.
A solution would be put a valve with a drain cock outside the crawl space and shut it off and drain the line in the winter.
This is called a stop and waste, (see image) and we were installing them back in Wisconsin long before anti-freeze hose bibs were invented. Just make sure the stop and waste valve's installed in a warm protected area. This will drain the entire line in the crawl space much better then a anti-freeze hose bib would because the anti-freeze part of the hose bib would still be in the crawl space where it and the line would freeze.
I would opt for the stop and waste valve from the git-go. Good luck, Tom