This page contains various house rules, rules tweaks, and new systems that make GURPS a more suitable game for my play style.
Establish point spending limits. Possible limitations are to Stats, Skills, and Advantages. Use this to help balance the characters.
Disadvantages should be split into pure mechanical ones and ones that are just colour. Those ones should not grant points at character creation, but in play instead. Also get rid of troublesome disadvantages: ones that affect everyone, even though they only give points to one person (enemy flaws), ones that deal with wealth (one guy could be the money guy, the rest poor to get more points), the ones that give points for just being a PC (weirdness magnet), other ones that don't fit.
Stats should start lower than average and not allowed to be bought down. Maybe at 8.
Get skills organized so that nothing but Bang! skills can be used, for pulpier games. Start with the official list and work from there.
Establish point cost maximums for any one skill to avoid one skill wonders, combat gods, and other over-specialization.
Create a Resources subsystem to replace standard Wealth and individual cost tracking. Wealth should just be a score, and Cost a difficulty affected by Legality.
May not be possible without a lifepath system. Also would be extemely difficult in a settingless generic system. Could instead use the current advantage system to show familiarity with certain groups of people and allow NPCs to be created with those rules. Don't forget the enmity clause.
Create a Social Conflict Resolution system. Duel of Wits is still the gold-standard, though others have good systems too.
Adapt from Nemesis and Unknown Armies. Make sure the various Advantages and Disadvantages reflect this system.
Adapt the essence of the Gumshoe system. Or at least use the advice to tool the existing skills for investigation.
Eliminate it in favour of critical failure that results in the weapon running out.
Create generic broad categories of weapons, but make sure there are enough categories to still have variety. Examples would be light, medium and heavy pistols instead of just one generic pistol at the simple end of the spectrum, and individual, very similar 9mm pistols at the complex end.
Develop a Savage Worlds style roll-over a threshold damage system. This is a more distant plan.