So, about rejects.

Switching to stratum-eu had not helped.  Still was getting the avg reject rate of 10.5%

So, I played with cgminer settings a bit.

1) Lowered intensity from 19 to 18.  That helped immediately dropping reject rate 2 fold.  Seems like high intensity works badly with some of the smaller coins out there.  Downside was the raw hash rate decrease by 20KHash/s
2) "expiry" : "1", "queue" : "5", "scan-time" : "1" - helped to cut off around 1% of rejects more
3) "failover-only" : true - does not help with rejects, but does not let cgminer to switch to backup pool during coin switch.

All that together brought avg reject rate from 10.5% to 4% during the first 4-5 days.

Lately it dropped even further to 3%, but here I'm not that sure if the chances irons out with time, or it has to do with DOGE we are mining most of time lately.

kudos for most of tips to @kenshirothefist on hashcows topic.