Possibly daft(?) questions about popping

Quick question, because I'm admittedly pretty clueless about balloon twisting protocol...

When starting out with balloon twisting, how much balloon popping is acceptable/expected to be considered 'good enough' to be doing ballooning gigs like birthday parties etc.  I'm assuming *some* popping is inevitable...you're going to come across the odd faulty balloon and that can't be helped.  Like is one pop every five or six balloon designs okay?  One or two pops per hour of twisting?  What is an acceptable poppage rate?  Or is any popping at all considered a faux pas at a paid gig, and to be avoided at all costs?  

And in a related question:  Breaking off unused sections of balloons - sometimes when I do this it makes a loud bang, does 'quiet balloon reduction' come with practice? or am I just doing it completely wrong if this is happening at all?

Oh, one other question (may as well add it here, rather than start a whole new thread)  -  Do black and chocolate Qualatex have a tendency to be weaker?  I got a 100 count bag of  'character assortment' 260's and almost ALL the blacks and chocolates either burst on inflation,  or burst on the first twist.  Wondering if this is a general problem with them, or were they just stale stock perhaps? The whites, blush & greys in the mix were all fine.

I am thinking they may have been stale/defective...

Are you burping your balloons adequately to have so much popping going on while you are twisting?

I can't break my balloons, so I tie a pair of scissors to my bag/apron.

You could of gotten a bad batch of balloons...also black and the darker colors are a bit more fragile..also as annie said you should burp them also don't over inflate.
also as far as the balloons popping while twisting..it happens...i have seen it happen to the teachers as well..some times you may go for several hours without popping and other times they will pop..
you will get better with time and get to know the felling of your balloons as your twisting..this comes with practice..

Maybe it is lack of burping -? I had not been burping all balloons...only the ones inflated almost all the way. I was thinking that if it was underinflated with a tail then it wouldn't need it. Have started burping them all just a little now, hopefully that'll reduce poppage. I mean, they're not popping ALL the time or anything (except for the dark browns & blacks which were giving trouble), but enough to think I couldn't ever do this for a paid gig with popping going on.