I figured those questions were probably already asked, since I couldn't find related threads I am asking again.

1) how to enable icmp requests? At present ICMP is filtered and I found no indication of ICMP configuragion anywhere on the router's interface

2) how to set ipv4 as priority over ipv6 when they are both enabled ? As much as we want to move on to the next internet protocol, putting ipv6 as priority makes no sense experience-wise and only serves as an additional delay between me as a client and https or other servers etc. so I really want to switch the priorities, as a home grade device setting  ipv6 under priority as default by the router is annoyingly nonsensical and reflects poor in depth design by TP-LINK considering the target audience imho.
 

I'll be happy for answers regarding the two.