Advanced Security Checkups can be easily conducted within the Reports tab in the Logs & Monitor view in SmartConsole. The Reports tab allows you to generate and view various reports that provide insights into the security status and performance of your network. You can use predefined reports or create custom reports based on your needs. You can also schedule reports to run automatically and send them by email. Some of the predefined reports that can help you conduct advanced security checkups are:
Security Overview: This report provides a summary of the security posture of your network, including the number and severity of incidents, the top attacked hosts and services, the top attackers and attack methods, the top detected threats and vulnerabilities, etc.
Security Best Practices: This report evaluates your security configuration and policy against the Check Point best practices and provides recommendations for improvement. It covers areas such as firewall policy, NAT policy, VPN policy, identity awareness, threat prevention, etc.
Compliance Status: This report assesses your compliance level with various regulations and standards, such as PCI DSS, ISO 27001, NIST 800-53, etc. It shows the compliance score, the compliance status of each requirement, the compliance status of each gateway and blade, etc.
Network Activity: This report shows the network activity and traffic patterns on your network, including the top sources and destinations of traffic, the top protocols and applications used, the top bandwidth consumers, etc.
System Health: This report monitors the health and performance of your management server and gateways, including the CPU utilization, memory usage, disk space, network interfaces, etc. Reference: R81 Logging and Monitoring Administration Guide

High alert is not an alert option in Check Point. Alert options are ways to notify the administrator or other parties when a security event occurs. The available alert options are SNMP, Mail, User defined alert, Log, Popup alert, and User alert. Reference: Training & Certification | Check Point Software, Check Point Resource Library

The vpn tu command and the SmartView Monitor are two components that allow you to reset a VPN tunnel. The vpn tu command is a command-line tool that lets you view and manage the status of VPN tunnels on a Security Gateway or cluster member. The SmartView Monitor is a graphical tool that lets you monitor the network and security performance, view VPN tunnel status, and reset VPN tunnels. Both components can be used to reset a VPN tunnel by selecting the option to delete IKE SA or IPsec SA for a specific peer or all peers. Reference: R81 VPN Administration Guide, page 29-30; R81 SmartConsole R81 Resolved Issues, sk170114

Captive Portal is one of the authentication methods used for Identity Awareness, which is a feature of Check Point that enables you to identify users and apply security policy rules based on their identity. Captive Portal redirects users to a web page where they can enter their credentials and be authenticated by an external server, such as LDAP or RADIUS. After authentication, users can access the Internet and corporate resources according to the security policy rules that apply to their identity.
The references are:
Machine Authentication & Identity Awareness - Check Point CheckMates
Check Point Certified Security Expert R81.20, slide 13
Check Point R81 Identity Awareness Administration Guide, page 9

The NAT property 'Translate destination or client side' is used to determine whether the destination IP address of a packet should be translated on the client side or the server side of a connection. If this property is not enabled, then the destination IP address is translated on the server side, which means that the gateway takes care of all details necessary for NAT to work. The gateway will send an ARP request for the translated IP address and will reply to any ARP requests for that address. Therefore, there is no need to configure a host route, use the local.arp file, or enable bi-directional NAT for NAT to work correctly. Reference: R81 Security Management Administration Guide, page 1010.