If you struggle on you'll just have to play smarter, keep food on you at all times and make good use of cover to slowly chip away at the bosses.
I just played my first time through to completion, concentrating on the cases and only working on other stuff when I had time to kill.
If you want to level up first go out into the park and directly across (and a little to the right) you'll find a parking lot with a car in it. Get in the car and drive around the maintenance tunnels (the entrance is right there) this is the fastest way to level up, it's also a great way to get the Zombie Genocide achievement.
If you do that don't expect to do anything else, basically just start 72 hour mode and go straight to that.
I did this after I finished 72 hour mode, basically just started a new game with the intent of getting Zombie Genocide.
What I did was grab some OJ in the coffee shop in paradise plaza, jump over the railing onto the awning for the Katina then run and get the car, I went straight into the room with the maintenance key (check the map it's the short road in the center that's a dead end) also in there is a machine gun and a few sledge hammers.
Go back out to the car and head to the Paradise plaza door in the tunnels (the far right on the map), go through the door and take the elevator up and it will dump you right by the bathrooms so you can save.
Go back down the elevator and get in the white car. Drive the car directly to the top left of the map. At the dead end there will be a large group of a few hundred zombies, do donuts here with the car until you kill most of them, then drive down the road a very short way (until you get to the first bend) and turn around, when you get back up they will have re-spawned and you can keep doing donuts. When your car breaks down enter the double doors there into the butcher shop. If you need it head left and there are two meat cleavers and two milk bottles here on the tables. Otherwise just turn around and exit back into the tunnels (this will re-spawn the cars), jump in the truck here and drive back to where the white car spawns... then drive the white car back up to the top corner and start doing donuts... keep repeating until you get what you're looking for. If you're efficient about it, you can take out about 1500 zombies in a single cycle. Every 10K or so before you get in the white car, go up the elevator and save again. You can do this whenever you feel like it to.
Once you're at level 30-ish you should be good enough to take out zombies with your bare hands and hopefully you will have learned the Double Lariat skill at this point. You can then just run into the large group and use the Double lariat to take out swaths of zombies for the Karate Champ achievement (1000 zombie kills with your bare hands). I did this to as many zombies as I could before and after entering the butcher shop in my routine, until I had the achievement then I went back to just driving. I was about level 36 by the time I reached zombie genocide with 9 hours left until the chopper arrived. You could keep doing it until level 50 if you like. If you run out of time you could just save and start 72 hour mode again. (levels will carry over but zombie kills do not, they reset with every new game)
It takes a while but you'll be pretty damn powerful once you're done.
As for the Camera guy, watch him when he does his flying kick move, there will be a yellow "PP" tag near his head, take a picture of him in full frame when the PP tag is visible for some great points. When he does his little victory stance after taking a picture snap a picture of him, keep doing it until you have over 700 PP in one of those photos (if you run out of batteries there's a camera shop right there where you can get more). After you meet that challenge he'll then challenge you to best him at an erotica shot. One of the upcoming scenes with Jessie is great for this and you can score 1200+ erotica, so pay attention.
He's just one of the many side missions in this game, don't get too distracted by them because it's near impossible to do them all in one play through.
This post has been edited by twistedsymphony: Oct 11 2006, 01:33 PM