Yes, much better selection. Friction mode will be fine, even indexed on the rear if the bar end shifters are Shimano 9-speed. Indexed front won't work so well- MTB and road front derailleurs have a different cable pull ratio.
The only difference between 8-speed cranks and 9-speed is that the 9 speed have slightly less distance between the rings. Either will work absolutely fine with a 9-speed chain.