If your on a android device, tapping a post brings up the edit option, If this option is Not available when Post is selected then it is most likely a error on client, I recomend using Google chrome for mobile site use, from experience. Default browsers might have difficulties with the ui. if the problems are hindering you, you can try using the desktop site, But I would Not recomend it on mobile
Linking as far as i am aware is a limitation for the mobile site. And Is probably going to be implemented in the future
Hope I helped!