This talk is focused on using neutral atoms in highly-excited (Rydberg) states for creating long-range molecular bonds and for sensing AC/DC electric fields. First, a new molecular ion formed through electric multipole interactions between a Rydberg atom and an ion is presented. Its vibrational spectra and stability against nonadiabatic effects will be discussed. In the second part, I will present our recent experimental investigations on whether Rydberg-atom-based sensing would be practical for electric microfields that occur in ion clouds and plasmas. The talk will be concluded with a discussion of the ongoing efforts to use high-angular-momentum Rydberg states for electric-field sensing in room-temperature vapor cells.