It is very common.  But only with friends.  Try not to use bad words in a professional situation or with older family.  

On another note you could actually say. "As of yesterday we've been doing things this way". In this situation it would mean "since".  But I don't use it that way often. Both are correct

Or an angry boss may tell you "As of right now this is how you will do this!" To use a little authority.

As of last week the plans were to buy a bike. 


The undertone is that you don't know if the plans have changed since that point.  They may have bought a motorcycle instead, but you don't know. 

they could both work. I'm sorry I have to be the one to tell you this- puts the emphasis on the fact that other people could have told you but I am the one forced to do it. Like the speaker would prefer someone else told the bad news. To me it feels like the speaker is making themselves the subject of the sentence. I'm sorry to be the one to have to tell you this- this is a little more polite. It puts the emphasis on the fact that you regret having to tell the person the bad news. Like you feel bad that the person has to hear it from you. Now in real life nobody cares or pays attention to this . They are equal and no one will take offense to either

colloquially you can say "The walls are paper thin"

Perk in English is equal to "Bonus" or "Something extra"

This term isn't used much. One would normally use it when you are talking about one thing that some one has, but want to point out that this person had more. He had two beautiful dogs that were well behaved, and two that were not. Altogether he had 4 dogs. Altogether he had 10 fish, but this one was his favorite. you can replace it with "In total" or All in all" igual a <En total> en español.