melee range = bad. But yeah, crowbars or axes are both decent utility weapons to carry with you. You can use them as a weapon in an emergency and use them for other things otherwise. But a crowbar id say not the best because you really have to SWING to smash a skull enough to brain a zombie. I mean, you have to REALLY commit to the swing to turn a brain to mush unless you have a nice long crowbar to add extra momentum.
Boar spear? Thats only marginally useful and only if you are in a group. If you want to hold a zombie back with one, you will need both hands to keep him back, leaving you stalemated. With a partner to go for the kill while you hold them off, it could be ok though.
Meteor hammer? No, its a fancy weapon that takes training to use properly. Stick with a spiked mace for skull smashing weapons.
I would suggest using bullets as much as possible, if only because they are the safest and easiest ways to take down lots of zombies without much personal danger. If I am going to mix it up in melee rnage with zombies, I want to know I took out half of them at range first. Yes supplies are a problem, but all it takes is one or two decent looting spots of gun and ammo stores or other places that sell bullets to supply you for taking down hundreds to thousands of zombies.
As far as gas goes, something to keep in mind is, in a full on apocalypse, there wont be many people around anymore to compete with over gas pumps. You could likely last for a long time going from town to town refilling until the stations start to break down or run empty. However, I still wouldnt recommend using cars as they are big, loud, and the roads are likely going to be impassible for 4 wheel vehicles due to congestion followed by abandonment. Stick to bikes, or at best motorcycles with saddlebags, so you have a small enough vehicle to maneuver with around obstacles. Yeah the third resident evil movie looked awesome with its big bad convoy of survivors, but in reality, it would have taken years to clear the roads of cars so it was possible to drive on them. It would have been nice if it worked, from a supply transport standpoint, but its just not practical.