The streaming API can still be very useful, even without the snapshots. For example it can be used to get updates when a company of interest makes a new filing. Also, you can use the basic company data CSV as a starting point, and update it with the streaming API.
As for the FTP products, you can contact customer care at Companies House and they can set you up with SSH which will give you access to all of the free data products on their server. I’ve made a little list of them here on a website I started: List of bulk data products | CH Guide . Sorry the website is not finished yet, but you might find that list useful to know whats possible to obtain.
Let me know if you find that useful, or if there’s anything missing that I can add.
You should also be aware that the data format used is proprietary, and not a common one like CSV or JSON. You will probably have to write a custom parser to read any of the files. More details about this on chguide. I can provide assistance if you need any advice on writing a parser.