I have just finished reading more or less everything, and this is what i have in my mind.
Surely there are things already said by someone else 
- Crafting Skills:
What I have understood from what the staff said, is that Crafting Skill will be something easy and accessible to everybody - you will just have to obtain the base materials.
That said, looking at âmore complicated thingsâ such as the already mentioned +20% mining speed, i suppose that the recipe difficulties will not be given by a âhigh crafting skillâ -
[i imagine there will not be something like a âcrafting levelâ, probably just a title based on what you have crafted? like âelemental weapon masterâ if youâve crafted weapons of all elemental type, this can be connected to a skill that we can call âweapons loreâ wich gives a +3/5/7/10% dmg bonus based on how many weapons lore you collect? at that point you can have âloreâ skills (wich i think is something related to survival/exploring)] 
- so the âcrafting diffiulty levelâ will be given by the rarity of the materials, like elemental core/nodes needed to craft, dropped only by low chance from normal elemental monsters and with increased chance from stronger monsters and titans.
Quote from http://oortonline.com/
âCraft weapons, tools and equipment from resources found throughout the universe. Be prepared, you never know whatâs lurking through the next PortalâŚ
Craft bows, spears, crossbows, swords, clubs, staffs and more using the streamlined crafting interface. Add a rare material to the modifier slot when youâre crafting and discover which materials enhance recipes (adding damage, durability, range or speed).â
- Magic Skill
âItâs a kind of magicâŚâ
Someone already spoke about the good old âtrinityâ? Yes (i think it was @Zouls ?)
Warrior-archer-wizard = melee-ranged-spelluser
I haveânt understood if there will be a fixed class system or not, what i have in mind is something âopenâ⌠letâs say that a player can freely choose what he prefers without restrictions BUTâŚ
let me do a short exampleâŚ
If you wear a:
cloth armor > barely gives fisical protection, higher chance of having special properties (+5% dmg? partial âfeather fallâ? +mana/int?), no malus at spell casting dmg/speed, same bonus of leather armor related to dmg bonus based on âdexâ. good elemental protections.
leather armor > lower defence than a full plate armor, higher than a cloth armor, dmg bonus related on dex using ranged or melee weapon [(call it âfreedom of movementâ)(a conceptual, virtual âdexâ)], but you take a 45% malus on spell damage/casting speed. lower elemental protection than cloth armor.
heavy armor > best fisical/elemental def. no dmg bonus related on âdexâ. Spell dmg malus 90%, ranged weapon dmg malus 45%
that means: you have any shape you desire in any moment, knowing that you can go for a pure melee/ranged/spellcaster or a good sword&spell in leather armor⌠or a heavy armor to reach the best defences, improved by buff spells (only spells that are not affected from the 90% spell dmg malus), etcâŚ
I can go on with the example, but i should describe a lot of items (a wizard rod/stick, shield/1handweapon/2handedweapon related on skills you can use such as defensive stance or charge, hat/helmet/full helmet can interact with the visibility range, etc)
That said: skills interactions! what i imagin:
a wizard trow a fire spell on the monster, wich is now having some nice flames on him (fire DPS but also monster dmg increased and possibility to attach the fire to his targets) so that the archer decide to use a water arrow wich save the monster from the flames but blinds him (vapour). now the blinded monster is weak to lightning dmg.
water+wind= ice â monster is now weak to fisical dmg and stronger against fire
water+earth= monster movements slowed (a good combo for a solo archer)
earth+wind= erosion â earth DPS + 45% chance to blind
fire+earth= nothing, try another (you have just extinguished the flames on the monster)
and⌠elemental melee weapons have 10% chances to start a skill combo 100% to interact with started combos, elemntal ranged weapons have 55% chance to start a skill combo and 90% to complete the combo, elemental spells always (100%) give the chance to start a combo and 55% to complete it.
to start a combo: you are approaching a monster, there are several wizards that all together shoot theyr spells⌠the first one to hit open the combo and for 2 seconds you can interact with that type of combo, a new combo can be started after 4/6 seconds - as soon as the first combo effect expire; in this way you will have to be good at what you do, you will not be able to use âalways the same 3 spellsâ or weapons.
note that i am assuming that skills will have cooldowns, mana cost and more interactions with other things⌠example: a warrior with full heavy armor will charge with a bonus damage higher than a light armored warrior (âchargeâ damage related on equipment weight?)
i believe that this way a really high number of things can be done and be added in the future.
As i said in the first part, speaking about âweapons loreâ can be extended to all of the sections - in this way players will have some kind of specialization, but reachable by everyone, you will just have to choose if you want/need that specialization or if you are not interested at all (i will never use a ranged weapons/my friends use ranged weapons no need for bow specialization)
All of my examples are done to explain a system and not to propose specific powers, as @ben said
So imagine like⌠[quote=âben, post:11, topic:289â] Blue could = Moon [/quote]
What is the effect of the Moon on the earth? Sea tide, romantic effect on people and animals (a scientific research prooves that sheeps goes on romantic mood during full-moon nights); romantic=charme and sea tide=gravity effect,
so i would say:
Blue=moon > charming spells, gravity effects (suh as ârock pillars emerge from the groundâ), earth type of damage
easy one: Red=passion > emotional buffs, (rush for movement speed increase/rage for dmg boost/charm removal/etc), fire type damage
as usual, i hope that i expressed in an understandable way 
edit: sorry for the long post⌠O_O