First you must find a weapon's weak and strong points in killing your opponent
For instance, the Hurricane weapon is not good for long range, so as your backup weapon, you should use a long range weapon.
The hellfire is good for close to mid range but in long range it is not accurate. Also be careful of the hellfire's low clip, some players can use this time to change you into money. If you use the Gravity hook to scale walls and ceilings, this could become a long-range weapon.
Antimatter Jet or Devastater is a real good for close quarter combat, because it can do good damage with a decent rate of fire.
The Plasma Cannon / DualCannon are very good picks, the DualCannon is good because it can do higher damage, and it is good for close range.
Ripper / Mag-rail / Auto Rifle can do some damage because it has a high rate of fire, so it is good for long range but the damage in general is very little, excluding the ripper. Mag-rail
is the best choice because it's fast, powerful and very deadly.
You can pick up the damage amplifier for give you more damage to kill your opponent or kill tankers.
Vaporizer is an instant deadly weapon, it has good range, high rate of fire but low ammo. Allthough, this weapon can reveal you while in cloaking or your sniping spot because it has a red line when you fire, which is easily traceable, so they can find you and kill you first.
Titan / Rocket Launcher is good for close range. The splash damage can make someone fly across the room, disorienting them a little.
stinger is cross between vaporizer rate of fire and ripper damage, because you must have to direct hit this weapon has a small splash damage and rocket must have a time to travel so you should pair it with a weapon that is better at close range or quicker to hit with.
Menacer is a timed mine. To make sure no once comes to you, you can shoot at the floor, making a barrier, letting you escape in the precious time that you have.
All in all, it is good to have a variety of weapons so that you can be a good, all-round player, from any range.
Airborne. It has great jump, fast, but weak. One of the best techniques with a close quarters weapon is to jump and land where the person will be; this disorients them and they cannot aim at you very well.
Exoquatic It has 1/3 the jump of Airborne, 1/3 the speed of Infiltrator,swim speed, and can hold it's breath forever.
Albatross armor is very agile armor is fast, high jump but it not fast like Infiltrator or jump high like airborne, but it has low armor like airborne and Infiltrator. This armor is better in the longrun.
Sniper has cloaking and is fast but extremely weak. With this armor, you can hide and shoot at players passing by or fighting from long range without being found. This is ideally in a corner, or in shadows. Sniper also over-rides auto fire used on them.
Sentry has cloaking too, with lousy targeting sensors.
Assault is a good armor, slow, but has good targeting, which makes it a quick killer.
Offworlder Most like sentry, It has a high jump, but it isn't agile like albatross because is very slow like tanker.
Tanker very slow so be careful in water or running around, snipers can pick you off very easily, and has very low jump.