I do mainly surveys and shopping through SR. The surveys do not require a physical address, and I do not get spam from the Greenfield surveys (worth 80 cents per day). SR does not send spam.
There are also OTX surveys on the site (in the offers section) for 75 cents per day. You do not need to put an e-mail address to do those - they are tracked by cookies.
I have done some paid offers of things I really wanted to try, like Blockbuster and the New York Times. I used my regular e-mail and did not get spam.
I used to do the free offers using a gmail e-mail address and a phone number from Private Phone. The phone number was a real, free number that went to voicemail, so I could check it when I wanted. That company is not offering free numbers anymore, although some other companies apparently are. I did put my real home address and got a few more pieces of junk mail, but not many. My gmail address was slammed with spam, though. I don't do the free offers anymore because I refuse to give out my home phone or cell phone to marketers - they will call you!
The e-mail address you use for offers does not have to be the same as your SR e-mail address.
I try to do all my shopping through SR to get the percentage back. I used to use Upromise, but I like seeing my Disney account add up. I don't do any more shopping than I used to, but I sometimes by from a different merchant because I know I can get money back into my SR account. SR has so many merchants that I use anyway - Land's End, Disney Shopping, Coldwater Creek, Gap, etc. Cindy can get most of the free shipping and discount codes that are on other sites.
I have $475 in Disney gift cards for our trip in 12 days, all from SR. It is a great site! Check out the forum at SR to get more tips to make money.