Red locktite on freeze plugs?

Now that's an awesome bit of information....

So are those plugs used for freezes to keep the block from cracking at all?

Or were they strictly for sand removal?

Sand removal.... If the block freezes, the water won't push the freeze plugs out...

If you think that your engine/block may freeze during storage, remove/loosen the radiator cap so the water has somewhere to expand and not put pressure on the block and crack it...