I am looking to purchase some Targeted Reddit ads for my gaming news site, and I am wondering would I put my site at risk if I did this? I've seen many big sites with Adsense on have ads on Reddit, also, can someone give me a rough figure on how much i should be making with around 3k visits/5-6k pageviews per day with a gaming news site. Over 90 percent of traffic is organic traffic and mostly for European countries.

Also best adsense placement and sizes?

I've got 250x250 image ad, sidebar
I've got a 728x90 header ad, text and image - this fine, or should it be just text, or just image
Also, one 250x250 image/text ad inside posts, should it be both or just image or text ad?

thanks for your help.