I completed "Gripped!" and the Shoreside Vale rampages (they are a lot harder if your enemies have AKs but still manageable). "Gripped!" is next to impossible to complete on rainy weather. That's probably mostly why you couldn't do it.
Here's the save: http://gtasnp.com/41816
I didn't complete any of the other stuff since it's relatively easy to do. You can find guides on the Internet for hidden packages and unique jumps. "Firefighter" can be passed by using the replay glitch (start the mission and press the replay button as soon as a vehicle appears on the radar; repeat until you get 20 fires extinguished on each island). You can also use the escape (pause) key glitch on "Vigilante" (as soon as you get close to a suspect's car press "escape"; they should get out of the car and you can run them over. Be careful though. Some of them may carry a rocket launcher.).
Also, in the future use this topic for SnP requests: http://gtaforums.com...ms-save-n-play/