The only time I've experienced problems related to earning to much is when I've joined a site and made 20 or 30 bucks in a couple hours. Don't get me wrong most legitimate well known sites will not ban you for earning to fast. But what happens is you generally set off some red flags and you will have to answer questions and most of the time provide an ID to verify your identity.
That being said the small less known sites can really get upset if you earn to much to fast and with some of the less reputable sites they can and will ban you for fast earning when your account is brand new.
I've found that most sites don't care how fast you earn after your account is 2 to 4 weeks old and you've made a few cashouts.
Center of prizes banned me for earning around five bucks in a few minutes. They said I had to be cheating that there was no way I honestly made the offers credit that fast, it is just not possible they said. I tried to explain that I simply was experienced and knew what I was doing and they responded by saying some BS like," do you realize that less than 5% of these offers generally credit people" so I told them they should advertise that on there web site. LOL, come to center of prizes where 95% of our shit will not pay you..
It's best to start out slow especially on lesser known sites. Points2shop is another one who will block or ban for fast earning, and it can take them months to answer tickets. Honestly they just responded to my ticket about being blocked the other day and it took a little over 6 months for them to answer me and unblock me.
If you are experienced and know how to make offers credit then GRINDABUCK is a good site to use. They do not care how much you make or how fast you make it . they will never block or ban you for fast earning. I saw a guy last week who knew what he was doing make over 40$ in around 2 hours on Grindabuck. Where many sites would question, block, or even ban for this that is simply not how they roll at GRINDABUCK. They were like, hell yeah keep it up. Keep in mind you must verify your identity on Grindabuck in order to redeem any rewards, they have two choices, you can verify by sending the admins a copy of your valid state ID or you can use there automatic background check system, but that method does require your SSN