In general they are treated nicely. I always used to work with Qatari ppl & they all treated me very well with lots of respect. I'll narrate just one experience:

In one of my previous jobs 6 Qatari ladies were my assistants 2 of them were financially not very strong but when I resigned due to some injustice happened to me all of them came to me & were about to resign when I stopped them. This kind of respect was not even given to me by my Pakistani counterparts but I was very touched & I always pray for them & will remember their gesture for me.

Regarding this second class thing this is very clear that the nationals of any country are the first class citizen & expatriates / immigrants are scond class which is not something to be frowned upon. Keep doing the good job & you would automatically earn respect :) cheers :)