These are among investors’ top concerns following Facebook’s unveiling yesterday of its Facebook Home smartphone super-app, which will put its services front and center on Google‘s Android operating system. It’s an important initiative for Facebook. Many on Wall Street fear that the social network company is caught in a dilemma: It needs to sell ads, but will turn off lots of smartphone and tablet users if it clutters their small screens with sales pitches. That’s why Sterne Agee’s Arvind Bhatia says that early versions of Facebook Home will be ad-free, but “over time the ‘Home’-based home screen will start to display very relevant, targeted, slightly larger, and visually appealing ads –all positive for ad rates.” If that happens then “Facebook Home will be a lot less appealing to consumers,” BTIG’s Rich Greenfield says. Even without the ads, he wonders whether many users want their news feeds prominently displayed on their home screens noting that “always on pictures from what you/your friends/your family did last night could be a wee bit embarrassing when you turn on your phone next to someone.” He and others also want to see whether Google will see Facebook Home as a threat. Although Greenfield says that Facebook won’t know what Android users do in other apps, the company still “is getting some important data that may not be in Google’s long-term interests.” The search giant could change licensing terms for Android if it concludes that Facebook Home diminishes the prominence or appeal of its services including Gmail, YouTube and Google Play. Pivotal research Group’s Brian Wieser notes that the initiative looks “provocative towards Google.” If software developers have to make adjustments for  their apps to run next to Facebook Home then “the appeal of Android might diminish — or apps will come to Android later,” he says.