I've received a payment for something in Bitcoin. The sender used blockchain.info's "shared send" to send to my account and it looks like it's coming from many addresses.
If I deposit this into an exchange like bitstamp, is this considered taint and will they cause issues with it? Especially of course if I would try to withdraw my coins?
We're talking a few thousand dollars-
I'm not aware of any exchange or legitimate service taking the concept of "taint" seriously. Bitcoins are fungible. Any legitimate service recognizes this fact.
Now, if you received directly from stolen bitcoins, you might find law enforcement knocking on your door and asking where you received them from.