Bronze became popular before iron because alloying copper to make bronze was discovered long before iron smelting was discovered (smelting = turning ore into metal). Iron was used before iron smelting, in the form of native iron (i.e., iron found as metallic iron rather than ore), mostly meteoric iron. Tools and weapons were sometimes made with meteoric iron, e.g., Tutankhamun's meteoric iron dagger:
but these were rare and expensive - the gold-bladed dagger also found with Tutankhamun was likely the cheap-and-nasty companion to this iron dagger. (Iron smelting had been discovered, but had not reached Egypt yet.) Tutankhamun's iron dagger demonstrates that key iron-working technologies, such as hot-forging and forge-welding had been developed. With these, depending on the object, iron can be easier to work with than bronze. Typical Bronze Age bronze alloys need to be cold-forged (and annealed by heating and quenching as they work-harden), and this cold-forging needs more force than hot-forging iron. Bronze had the advantages that it could be cast, and some items were easier to forge (e.g, large thin sheets, or helmets, or breasplates and other plate armour pieces) because it's easier to hand such pieces when cold than hot, and they cool quickly if hot-forging (due to large surface area for their mass).
The high-tin bronzes typically used for edged weapons and tools were generally harder than their iron equivalents. They also had the advantage of much better corrosion resistance. Iron was functionally inferior. Meteoric iron had the advantage of rarity making it valuable - an important consideration when making prestige items. Where the meteoric iron was identified as stuff having fallen from the sky, it also had the magical advantage of being "sky metal". Once iron smelting became reasonably common, iron became much cheaper than bronze. Iron ore is very abundant, and bog iron and iron sand can be collected without the difficult process of hard-rock mining. Copper ore is less abundant, and more likely to require hard-rock mining and/or underground mining. Tin ore is even less abundant. Iron was not a better alternative to bronze, but a cheaper alternative.
Later, hardened steel provided a superior material, much harder than both bronze and iron. When iron was first replacing bronze, hardened steel was still far in the future.
As for aluminium, aluminium is very abundant in the Earth's crust (third after oxygen and silicon), and aluminium ore is common. The difficulty is smelting aluminium. Copper, tin, and iron are usually smelted from oxide ores (non-oxide ores are commonly converted to oxide ores by roasting (heating in an oxidising atmosphere). To smelt the ore, the oxygen needs to be removed, and the usual process is to heat the ore with carbon - the carbon will bond to the oxygen more strongly, and pull it off the metal, converting the ore to metal. This won't work with aluminium - it bonds more strongly to oxygen than carbon does. Today, electrolysis is used to convert a molten alumina (aluminium oxide) solution to metallic aluminium. This needs electrical technology, and was not possible before modern times. This means that aluminium only became available long after hardened steel was available for edged weapon and tools. So it hasn't ever been attractive for edged weapons and tools. Today, many tools are made of aluminium (especially cookware) or have aluminium parts, but aluminium sharp edges are very rarely used.
Aluminium would not be attractive for edged weapons/tools even in the absence of hardened steel. It is harder than copper, but softer than wrought iron and high-tin bronzes. The Brinell hardness of aluminium is about 70, vs 105 for wrought iron, about 100 for 10% tin bronze and 160 for 20% tin bronze (and bronze blade edges are typically harder due to work-hardening by hammering). For comparison, mild steel has a Brinell hardness of about 130, and hardened steel about 600. (Brinell hardnesses depend on the test conditions, and I've tried to find values for similar test conditions).
No. Aluminum is quite easy to melt and cast, it's true, and it's very abundant as an element in minerals. But because it combines with other elements very readily and those compounds are very stable, it does not exist in nature in metallic form and it's very hard to refine. It was not until more was learned about chemistry in the 18th c. that it was thought to exist, and it defied industrial refining until the mid 19th c. , when Frenchman Henri Sainte-Claire Deville came up with a process- and that first required making metallic sodium! Though Napoleon III was very intrigued by the possibility of using the new metal for weapons and armor, even then it was far too expensive, worth more than gold by weight..
