Mages, gear and melee. A personal view.
Melee A melee character power is proportional to his equipment. His damage output will depend on his weapon, on his damroll, on his hitroll and his skill %. Typically a well dressed melee will walk around in +50/+50. For example a melee (if we state that enhanced damage give +50%) with a avg 27 weapon will give 40.5 damage base. The damroll bonus will double that value. Imagine a melee gets a equipment that improved dirt kick. Now his chance to fail dirt kick will decrease from 25% to 20%. Every proficiency gear aids a melee. Specially weapon proficiencies.
Mage A mage power mostly depends on his class selection. And a very tiny bit on additional spell level equipment. The single thing a common mage can do to improve his spell damage is to gather a piece of eq that increases his spell level. Even this will not be much. Let's say I use a spell that deals 200 damage. This is most times in FL something close to damage = Level x 4. Raising my level to 51 means that I increase damage by 1/50. 200 becomes 204 and so on. L52 => 208, L53 => 212. Most of the impact come from the fact that higher spell levels are harder to save against or cure. Let's say you managed to get max spell level and that this impact saves by +?? svs vs spell. So now your opponent saves your spells 80% of the time instead of 90%. If we imagine that saving the spell halves the damage. Then [(100x0.2+50x0.8)/(100x0.1+50x0.9)]= (20+40)/(10+45) = 1.09, which means you have increased your damage by 9%. Regarding spell proficiency, this has no impact in spell power, except for Battlemages who get some nifty bonus on a few key spells. For the most, gear that improves spell proficiency, just aids with not failing to cast the spell. This mostly only affects races like giants who can fail mastered spells, and mages who get furied by a feral.
HP Gear HP gear is interesting, as it extend the time a character can stay in battle before dieing. A elf mage will have ~500 HP base (pre trains). With 1 prac and train saving this can get up to 700 HP base (trained). Meeles tend to have ~1000+ HP. For them HP gear is not as advantageous as for a mage who can get +300 HP in HP gear, improving his HP by ~+40%.
AC gear AC reduces meele damage, which translates into more HP. From my experience I can get -300 AC in most characters, but to get -500 AC I need to really put some effort. This improvement in AC from 300 to 500 can mean an effective increase in HP by ~20%. In my opinion it's always more advantageous to take HP gear over AC gear, even in the debatable case of clerics.
Mana gear. Having more mana is always nice, but it improves little unless you are getting out of mana in PK. Which will mostly only happen for an unskilled player, or when your opponent erodes your mana.
Conclusion My main point is, more EQ always favor melees over mages. Yes, HP gear will allow a mage to live longer, but does not allows him to kill faster. Hit/Dam gear for meele increases their power greatly, allowing them to kill faster. Being able to kill faster is good because your opponent has less time to react, recover from mistakes or run.
A corollary of this is that an universe where cabaled players can be fully decked will always favor melees.
What can be changed? Easily? I have no idea. Changing spells to take into account spell proficiency would mean lots of code work. I hate save breaking equipment. (Having your gear decrease your opponent saves). It's counter-FL IMHO. The easiest would be to have more spell level gear. Which is the opposite of what has been happening.
Disclaimer. - All numerical values are not exact and intend only to be objects in comparisons. Don't go around saying I said "X affects Y by Z".