Explanation
Using --link to access the container on the bridge network does not make the container reachable from its host's network. The --link option allows containers to communicate with each other using a private network created by Docker. To make a container reachable from its host's network, you need to use either EXPOSE or
--publish to access the containers on the bridge network. References: https://docs.docker.com/network/links/,
https://docs.docker.com/network/bridge/

Explanation
This command does not list all nodes in a swarm cluster from the command line. The docker swarm command manages swarm operations, such as initializing or joining a swarm, updating the swarm configuration, etc. It does not show information about nodes or services. To list all nodes in a swarm cluster from the command line, you need to use docker node ls command. This command shows information about all the nodes that are part of the swarm, such as their ID, hostname, status, availability, etc. References:
https://docs.docker.com/engine/reference/commandline/swarm/,
https://docs.docker.com/engine/reference/commandline/node_ls/

Explanation
Using namespaces does not limit a Docker container's access to host resources, such as CPU or memory.
Namespaces are a Linux kernel feature that provide isolation and virtualization of system resources for processes. They can be used to create isolated environments for containers that have their own view of system resources, such as process IDs, user IDs, network interfaces, etc. However, they do not control how much resources a container can use or access. References: https://docs.docker.com/engine/security/userns-remap/,
https://man7.org/linux/man-pages/man7/namespaces.7.html

Explanation
Using either EXPOSE or -publish to access the container on the bridge network will not accomplish the goal of creating a container that is reachable from its host's network. EXPOSE is a way of documenting which ports a container listens on, but it does not open any ports to the host1. -publish (or -p) is a way of mapping a host port to a container port, but it does not change the network mode of the container2. By default, Docker containers use the bridge network, which isolates them from the host network3. To create a container that is reachable from its host's network, you need to use the --network host option when running the container4. This will make the container share the host's network stack and have the same IP address as the host4. References:
* 1: Difference Between "expose" and "publish" in Docker | Baeldung on Ops
* 2: Deploy services to a swarm | Docker Docs
* 3: Bridge network | Docker Docs
* 4: Host network | Docker Docs

Explanation
This configuration will achieve fault tolerance for managers in a swarm, because an odd number of manager nodes allows for quorum-based consensus among managers and avoids split-brain scenarios. According to the official documentation, having more than two manager nodes ensures that there is always at least one manager available in case of failures.
References: https://docs.docker.com/engine/swarm/admin_guide/#add-manager-nodes-for-fault-tolerance