Giving the painkillers to bill does count as "getting friends" to help, and prevents you from getting the Lone Wolf achievement. Even if he hadn't helped you with any tasks. You must kill bill (no pun intended) with the axe and without giving him the painkillers or alchohol. And you can't spare one bullet on him.
Money should not become obsolete near the ending of the game. At least provide us a way to spend it buying clovers (at a increasingly absurd rate). Maybe at the constructed house after you fully upgrade it. Gambling is also a good idea.
BO-RING!! The game suddenly became pointless, im just farming, and farming, no fun at all, everithing is too expensive and its hard to earn money.. Like this: Complete ride in story mode, half a minute and 20k.. Now repeat more and more in order to get an silly upgrade, and goes on.. Boring and pointless.. Still 5/5
IMPORTANT --- IF YOU ARE STUCK AT THE SNOW LEVEL: there is a bug after defeating 2nd boss (santa), you just start off in the snow level again. To pass to the water level just wait a second or two till two icons appear at the top of the screen and click in the igloo.. and a level select screen appears!! Congratz you just learned how to select your level.. :D