Dividend investors looking for high-yield stocks have to carefully balance risk against reward. Reaching too far for yield can leave you owning a struggling business that might someday cut its dividend.A good example of this today is British American Tobacco (BTI 0.31%). Here's why conservative income investors should pass on the cigarette maker's 8.1% yield and instead go with Realty Income's (O 1.99%) 6% yield.British American Tobacco's worrying business trendRoughly 80% of British American Tobacco's reve ...