Yeah the enemies get harder to kill and more dangerous as your "skill" points accumulate. However they both get maxed out which is kind of a bummer.
I used the hotrod mod on a machete, it is kind of cool looking. The "magic wand" mod you described is fabulous, on a gold construction hammer it is really lethal and durable, and can send even thugs flying away and breaking apart on impact. Very good physics on that one. Blade weapons generally have low durability (unless you throw them, which is a bit risky because you can lose them outright) and are expensive to repair, not a good bet if you are goal focused on building a war chest. Mine is fluctuating between $2.5-3m. In a good session I can gain ~$40-50k, and by periodically cashing out diamonds, blades, cans of food, and souvenir photos @ $2k with certain high-paying characters, you get fairly dramatic boost. Each time you get killed, which usually only happens to me when I'm shitfaced drunk, you lose 10%. Such are the economics of zombie-hunting.
EDITED: 9 Jan 2018 17:28 by DSMITHHFX