The options that are given on features, when editing a Role on Gaia Platform are Read/Write, Read Only, and None. These options determine the level of access that a user has to a specific feature or command in Gaia. If a user has Read/Write access to a feature, they can view and modify the settings of that feature. If a user has Read Only access to a feature, they can only view the settings of that feature, but not change them. If a user has None access to a feature, they cannot view or modify the settings of that feature.

Explanation
Harmony Endpoint is a solution that provides comprehensive protection for endpoint devices against cyber threats. Harmony Endpoint includes a personal firewall that controls the network traffic to and from the endpoint device, based on predefined rules and policies. Harmony Endpoint also integrates with Check Point's VPN solutions to provide secure remote access to corporate resources1. Therefore, the customer will need Harmony Endpoint because of the personal firewall requirement.
References: 1: Harmony Endpoint Administration Guide

If an administrator wants to add manual NAT for addresses not owned by the Check Point firewall, they also need to add the proxy ARP configurations in a file called $FWDIR/conf/local.arp. This file contains the mappings between the IP addresses and the MAC addresses of the NATed hosts. The proxy ARP feature allows the firewall to answer ARP requests on behalf of the NATed hosts and forward the traffic to them. The local.arp file needs to be edited manually and reloaded with the command arp -f $FWDIR/conf/local.arp. Reference: R81 Security Management Administration Guide, page 1014.

Explanation
https://sc1.checkpoint.com/documents/R76/CP_R76_CLI_WebAdmin/12496.htm