1 - Getting 3 stars in the first chapter
Before the mission, select a bought sawn-off shotgun, and a revolver. You will have to kill most of the enemies in the level with the revolver, so it may take some time. Use the "cover" (Square) ability often. After you approach her "cabin" on the left is a big rock, go behind it and stand, Do not use "cover", but face the opening where she runs at you with the shotgun.
On the level with the exploding dynamite Boss, sneak around and hide so that he does not see you. Note: Bongo music will play when he is on your tail. Then, shoot him with the rifle in the back. This surprises him (the game will say "You surprised him!"). Then, power on through with as many shots as possible to get his life down. Repeat the hiding routine, then sneak shot again.
After completing the Freak Show level, where you fight Professor Perry as Jack Swift, he will be in Brimstone. Keep talking to him and eventually he will sell you a maximum health upgrade.
During the Bar Brawl, go upstairs in the saloon and talk to the two ladies in the bath. You will get an option to take a bath with them for $1,500, which will increase your maximum health.
When starting a new game, instead of entering a name use the spacebar right to make a blank entry. When you enter this, it starts a character named "Rstar". In some of the stores some items show up as already sold to you. Additionally, when starting a new game, enter "ASSMAN" as a name. Almost everything in the stores will appear as sold.