Mining ERG is more profitable than ETC and more than ETH also 
You can also mine ERG+ZIL for more profit.
There are so many alternatives out.
Yes, it is. But as i see, right now nethash or ERG is x2 from week ago and grows up. And summary trading volume is about $15kk. If you mined ERG before - this is good time to sell. But to mine it right now - you can get some profit probably for 1 day, maybe less. You can also mine ERG+ZIL for more profit.
There are so many alternatives out.