IPv6 - Allow incoming ICMP echo requests

This first bit is not a direct answer to your question. I just include it here for others that don't realise the importance of ICMPv6.

IPv6 really needs certain ICMP message types to get through. The most important ones are Packet-Too-Big and Parameter-Problem. If you block those then you will get connectivity issues.

Also: the IPv6 equivalent of ARP is neighbour-discovery, which uses ICMP packets as well. The stateless auto configuration is part of neighbour discovery, so also needs ICMP.

In IPv4 there's is a misunderstanding that all incoming ICMP should be blocked, and you can get away with that. With IPv6 you really need to allow at least some ICMP. Take a look at https://www.rfc-editor.org/rfc/rfc4890, it contains some really good advice on how to filter ICMP without breaking the protocol.

The answer to your question Blocking incoming ICMP echo requests is fine. I personally don't do it because allowing them makes debugging a lot easier, but if you don't want to allow them in you don't have to. The main risk you run if you allow them in is that if someone finds a stable (non-temporary/privacy) address for e.g. your laptop then they can keep pinging it to see when it's switched on. That might be considered a privacy risk. They'll have to find such an address first though, because for outgoing connections it will use its temporary privacy addresses.