Holy simply means set apart. All followers of Yeshua are set apart, but some are set apart even from the others. I would agree with you though that it has less to do with occupation and more to do with commitment. So certainly, someone called to called to celibacy has been set apart in an extra way. But, in the modern society, someone called to polygyny or to having many children is also set apart. Is one more "holy" than another?
There are those that are called least and those called greatest within the Kingdom of Yah. It is not for us to judge arbitrarily (or really at all), but I believe the best way to look at people is through their fruit. Not by saying anyone celibate is better and anyone married worse (or vice versa).
I would say Paul IS scripture, but I think a better conversation would be trying to see if everyone on this forum agrees with what "scripture" means and, perhaps more importantly, what it does not. I don't think that everyone here is thinking the same thing when they say scripture.