If you had power room is it worth it to get more s9? Or wait for later in the year?
Personally I'd grab an 841 over an S9. Their price is under $1000usd, and Canaan is undoubtedly better than Bitmain. 841's come with warranty, and the reliability is great. Something new is definitely near, as prices are dropping.
Guys I've got stratum+tcp://de.kano.is:3333 as first pool, what should I put for second and third backup pool?
Ping them all, and set the fastest ones in numerical order. Thats how I'm set up.