How to license software from Microsoft in a small office?

Question

Licenses for software and other works

1. Windows 10 Home
If I bought a laptop with Windows 10 Home activated preinstalled. Can I use it in a commercial environment or do I need to buy Pro and upgrade the system? Basically, even if it's not pre-installed, can I buy the Home version, install it on a computer and use it in a corporate environment? (I'm not interested in missing features like the ability to RDP into a machine with a Home version, login to a domain, etc.)

2. Office for Home and Student
Same question for MS Office. For many users, Word and Excel are sufficient. The home version is much cheaper. I bought a laptop with a pre-installed office for home. Do I have to buy a business version or can I use it as is?

3. Domain
Let's say I installed Windows Server 2016, bought a license by the number of cores. Set up a domain. And he introduced 10 computers into it. The other 10 computers are simply on the same network.

1. Do I need to buy 20 CALs to use public folders on this server?
   
2. If 10 computers entered into the domain do not use shared folders, they will not use it as a terminal server ... That is, they will only access the server to receive group policies, check the user from Active Directory when logging in. Do I need CALs in this case?
   
3. If a guest comes to the office, turns on the laptop, connects to Wi-Fi and receives DHCP or makes a DNS query, does he need to have a CAL license? If so, even if it's Linux?
   
4. If I deploy an IIS web server, create some kind of cloud service. Well, like Gmail or Google Drive (just for example) . And I will have many clients. For example 1000. Will I have to buy 1000 CAL licenses?
   
5. If I install say FileZilla Server and my 1000 clients will use it as file storage. Do I need 1000 licenses?
   
6. If I will provide the "virtual machine rental" service. Now for a rough example. I will create a virtual machine in Hyper-V. I will install Windows 10 Pro there (Yes, this is important for the example, because Windows Server will be licensed at the expense of the host) and give access to the machine to the client. Do I need to buy a Windows 10 Pro license or does the customer have to buy it? Do I need to buy a CAL license for a client? And if on a Windows Server virtual machine. Do I need a RDP CAL for the client?
   

PS. Please do not offer to install Linux for everyone, etc. It is important for me to learn about licensing. Thank you!

Answer 1

1. Windows Home can be used in the office, but with technical limitations. The most unpleasant, IMHO, - passwords to network resources are not remembered.
2. Office Home and Student cannot be used for commercial purposes.

You must not use the following versions of the software in a commercial, non-commercial, or income-generating activity.
...
b. For home and study.

3. CAL is needed for every computer or user that uses at least one resource of at least one Windows Server (even DHCP). Accordingly, either Device CAL or User CAL are used.
Each device or user connecting via RDP requires an RDS Device CAL or RDS User CAL. These licenses do not replace the need for a primary CAL.
For anonymous access to a site on IIS or to files through FileZilla, a separate type of license is purchased - External Connector. If access with authorization - that CAL on each user.
You may only provide the Windows Rental Service, physical or virtual, by entering into a separate SPLA agreement with Microsoft and purchasing Windows under a special license.

Answer 2

I have one question, rage already appeared such a complete answer. And why do you need any licenses for filezilla? It's free software, you can use it however you like. What does it have to do with Microsoft licenses? If it is a separate program?