Bob, I'm honored by your comment because I have found your posts to be reasonable as well.
I agree that Informa is a good company to work and I would work with them again. However, I had repeated problems with not being paid the correct amount. Everything you posted above has been my experience with Informa except #4. I have not worked for Informa recently, NOT because of the pay issues (although the pay issues were a major PITA), but rather because they lost the contract for my favorite shop and I've not been particularly interested in their other shops.
I had pay issues 4 times over an 18 month period which were not quickly resolved. They required multiple e-mails and all but one took over 6 weeks to resolve. The problem appeared to be their accounting contact, who was not responsive; in fact, in each case the accountant did not respond until I began to cc the scheduler (even though the scheduler had told me "Don't cc me, I can't help you.") noting "3rd request" and "4th request, etc." After doing this a few times, each time I received a response from the accountant with an apology about how busy she is and she was able to quickly resolve my issue.
I do not believe that shorting me multiple times was deliberate, and I did eventually get paid the correct amount in each case. I think the pay issues were the result of disorganization and unresponsiveness, and perhaps those issues have been corrected. I responded to the difficulty by accepting only heavily bonused shops, figuring I was more willing to deal with problems for higher pay. I hope they have corrected this, because it was the only thing I could find wrong with Informa. I have not had the opportunity to work with Dylan, who has posted here in recent weeks, and I'm much impressed with him.
The main point, though, is that shoppers should keep track of the shops they have done to be sure they are paid for all shops performed. They should double-check to be sure they receive the correct amount for each shop. No one should take it for granted that, because they are working for a AAA company, that there will not be any pay issues OR that because they have received payment, they received the correct amount.