Router firewall ICMP risks and threats?

I have found out, that my Router firewall has never blocked ICMP traffic. There is a lot of opinions online regarding ICMP, and whether it should be disabled or limited. So far I have found out, that it can exploited to monitor network traffic / I/O traffic (man-in-the-middle). It can also be exploited to carry and infect a PC system with malware. My questions / worries are: 1. If someone monitored my network traffic using ICMP, would HTTPS traffic then still be encrypted / unreadable? 2. Would my Windows Defender firewall block an attack / attempted malware infection via ICMP? 3. Would Malwarebytes (example) scan detect, if my PC system had been infected by malware via ICMP? * Are there other ways someone can access my PC system using ICMP, besides via malware infection? Thanks in advance for your answers And happy weekend! Best regards
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