I did this and started noticing problems right away like flashing lights and grey lines on the screen the controllers have to be resynced everytime you turn the games on and off and sometimes the controller wont resync at all. so do not play gta or buy them i deleted them from my ps3 as a precaution and contacted customer support and told them the problems i as expierencing and they said that my ps3 was fine and that it wasnt malfunctioning at all because it wasnt freezing up when i used it.
downloaded or on the actual disc cause it only happens to me when i play gta vice city and san andreas downloaded on the ps3 from the psn store and i know i am not the only one having problems with it
hmm well they keep messing up on my ps3 i wonder if i got a crap download and should try again but i already deleted all my saved game data and stuff i would have to re download them again and start all over.
what i would do is as you already stated-delete all the game save data and then reboot into safe mode and do options 3 and 4 as these will not delete anything from your ps3 other than msg's but will straighten up the file system/database and then try and re-install them..you truly shouldn't have any issues playing them..