So your sources are a thread here with the first message providing no sources on the R-73 and the second message giving the correct number and 3 web articles of questionable quality… jesus…
Incorrect, TVC is very good at destroying all the speed the missile has. Lower speed means smaller turn radius, decreasing lateral acceleration. Here is a screenshot from a mach 1 shot and you can see its nowhere close to 45g during the peak of the turn. Additionally, the statcard G limit is practically useless, the maximum pull is determined by other aerodynamic and guidance properties such as PID, fin AOA, TAS.