We present a methodology for the analysis of the capacity and symbol/bit error rate performance of Alamouti space time coded OFDM links that jointly captures the aggregate effects of real life receiver imperfections and mobile channel effects. Specifically, we investigate carrier frequency offset, channel estimation error, outdated channel state information due to time selective channel properties and flat receiver I/Q imbalance. Hence, we provide a numerical tool for realistic Alamouti space time coded (STC) OFDM performance evaluation. The main contribution of this work is the derivation of the probability density function of the received frequency domain signal with respect to the mentioned impairments. The density function is then used for numerical calculations of both the symbol and bit error rates, as well as the capacity for Alamouti STC OFDM links. Finally, we illustrate which of the mentioned impairments has the most severe impact on the overall STC OFDM system performance. The abstract goes here.