A radioterminal may include a transceiver, a hand-held interface coupled to the transceiver, and an interlock coupled to the transceiver. The transceiver may be configured to transmit and receive wireless communications, and the transceiver may be further configured to transmit high power communications at a high maximum power and/or EIRP and to transmit low power communications at a low maximum power and/or EIRP. The interlock may be configured to prevent the transceiver from transmitting high power communications at a power and/or EIRP that exceeds a threshold when the hand-held interface is activated. Related methods are also discussed.