No.
All of his films released before 1923 are in the public domain.
No; his films would be protected by the production companies.
The broad assumption is that if something is in the public domain, there is no incentive for anyone to care for it. This is referred to as the tragedy of the commons, but has been fairly consistently disproved. For example, films in the public domain are much better cared for than films that archivists are prevented from migrating to new media by copyright restrictions.
No; the films are protected by copyright, and the name and character are registered trademarks.
The original novel will enter the public domain January 1, 2043. Films and other adaptations may still be protected at that time.
You can purchase an inexpensive compilation Dvd of public domain horror films at Amazon, Ebay, Craigslist, Open Culture, Yelp, and Dvd Talk, a review sight that also sells the Dvds they review.
It was not. MST3K usually featured older films than this because it was easier to use public domain films instead of trying to get the rights to films.
Remaking of films is allowed as long as you purchase rights to the story. Some stories might be "in the public domain" and you would not need rights for those.
A film appearing in the public domain means that no individual, organisation or government owns the film. It is therefore said to be in the public domain. There are a couple of ways a film could appear in the public domain. Firstly it was never copyrighted when it was originally released. Secondly a film enters the public domain if the copyright of the film has expired. How long it takes for a copyright to expire depends on a number of factors such as when the film was released and whether the copyright has been renewed over the years.
The only legal way to download films, or movies, for free online is to download public domain movies. Two sites for that are Public Domain Torrents and Public Domain Flicks. Otherwise there is no way to download free movies online.
Most Keystone Kops films were made prior to 1918; anything before 1923 is in the public domain.
You would need to find someone who owns a master and negotiate with them directly. Simply getting access to public domain films to watch can be done at the websites linked below and many others.