witness

Witness are the key part of the steem eco system which runs the network. They are rewarded from the rewards pool with steem!!! Everyone knows this, but I am wondering with the current value of steem around 20 cents,

is it possible to run a witness without loss every month?

is the reward adjusted to the cost of steem?

Is more witness needed in steem eco system ?

Should the top 20 concept be scrapped and expanded to include more witness in the rotation algorithm ?

All response welcome.