I noticed your wired setting for the gateway on your Linux machine is 172.16.42.1
While I'm still rather new at this, I'm thinking it should be 192.168.1.1.
I'd give it a try at the very least.
I do remember when I was setting up the Internet sharing on my Kali machine, I left the network settings as automatic. The only changes I made where done using the wp6.sh script.
As for connecting to your pineapple's interface...
Open up terminal and ssh into it.
It will prompt you to trust its certificates and then your wifi pineapples password.
It should bring you to /root#