Yes I did it and unfortunatly also Smiui doesn't have Gapps, so I installed the stock rom back again.
Furthermore installing the stock rom to merge the partitions CWM got replaced by stock miui recovery.
Same problem as Oscar on mi2s:
. No Gapps
. no keyboard
but partitions are merged!
Now I'm using the stock 5.5.22 with merged partitions waiting for solutions! Grazie.