The first bug is a programming error, and will probably never be fixed, it is a save game problem, the only way to fix it CURRENTLY is by deleting your save file and starting again; you will keep your speedpoints. BACKUP YOUR SAVE FILE FIRST, incase it doesn't fix the problem.
Secondly, to fix the second bug, ignore it unless it is causing issues in game.
Thirdly, the "nullo" is actually frame buffering, CLEAN YOUR DISC, and is caused by the "Need for Speed", literally, you are driving too fast for the game to render the new portion of track, so it will force a frame pause in order to buffer - one way to try and improve this is by freeing HDD space FIRST, and using the recovery menu to rebuild your PS3 database. Do this by turning of the PS3, then holding the power button down until the system shuts down again. Now hold the power button again, until the system beeps twice, and let go. Plug a controller into the system via USB and press the PS button. Choose the "Rebuild Database" option. YOU WILL LOSE YOUR MESSAGES and PLAYLISTS, NOT SAVEFILES or GAMEDATA, just non-critical data. Let it rebuild the database. *Also clean your PS3 out too, if it is dusty; buy a can of compressed air and blast air into the air vents, 3 second bursts.
The final bug is just stupid people, and won't be fixed because that is the way the game is meant to be played.
