The save screen glitching is common. You can either memorize the commands to save, or just keep exiting and entering the save menu and it will eventually appear normally. It will in no way harm your PS2, and shouldn't affect your ability to save at all. If it actually were a harmful glitch, I'd be screwed given that I've spent more hours playing FFV on my PS2 than I ever did on the PSX. Don't worry about it.