Does there exist a 'tier list' of cube archetypes that I could maybe use to deduce the general power level of the archetypes to include?
Well, there's a thread called "Archetypes", might be useful to at least take a gander:
http://riptidelab.com/forum/threads/archetypes.874/
In my mind, the major archetypes that are thrown around in discussion on most cubes are (some fairly obvious):
Rx aggro (recursive and not)
Ux control
Spells matter
Ramp
"Weenies"
Monsters
Skies/evasion
Reanimator
A
lot of cubes around here also have: Pod
I think a solid exercise to go through is figuring out what deck types there are/you like in every color pair, and looking at the ones you want to be using in your environment.
Taking UW as an example, a few solid options for that pairing might be:
Skies aggro
Draw-a-card.dec (think looters, jhessian thief, solid white removal and finishers, etc)
UW control
Blink value
Some of these might overlap, and that's fine. Finding spells that overlap is an exquisite pleasure in itself, and makes colors stronger overall.
Seeker of the Way is an A+ example of this sort of card, as are
Thirst for Knowledge,
vendilion clique, and
fiery confluence. I personally trimmed my section down to about three "archetypes" per color pair (Blink, Skies, classic control-tempoier). Note that doing this per pair will end you up with wayyyy more than 6-7 "archetypes". That's because archetypes in the Alphez post are more holistic for the entire cube. What 6-7 paths do you want your drafters to guide themselves down? For you maybe 8-10, cause your cube is bigger. They can be combinations of multiple color pairs, they can be available to virtually the whole cube (pod).
For example, imma look at "ramp". this is almost invariably a green-centric archetype. This drafter works the mana dork angle, going for big finishers with a smooth curve that enables plays on all turns. We can build up ideas from pairs and colors that can make the ramp deck happen, and in doing so provide a ramp deck of multiple varieties tied into individual things we want colors doing:
Green: we want a nice selection of high impact spells right in color (
vorapede, PrimeTime,
woodfall primus), and we need dork density.
Red: Have some monsters (
Crater Hellion,
thundermaw hellkite etc), and X burn spells shine here
Gruul: we decide this pair is focusing on the beats with monsters, combat tricks, and big removal.
Simic: We can put some big spells into simic. Gas up into big
genesis waves, power out a
Treasure Cruise, or slam an early
Sphinx of Uthuun. Gives us options into mass bounce (
cyclonic rift = yay)
White: Angels. Boom. Value enchantment removal backs up our feathered friends
Selesnya: we get X spells, token makers, big doods. Selesnya = maximum dudes on board (
armada wurm 
)
In this way we take what I'll call color pair
identities, combine them with what you want to be doing with your colors, and the Ramp.dec becomes an archetype, flexibly enabled across multiple colors. Black can easily be added too, often partnered with the reanimator archetype (ramp = backup way to get early big dood). Important step is reading up/knowing what holistic-style archetypes want to be doing: ramp is going for early mana acceleration to make up for a normally too-high curve. Early value creatures help carry the deck into it's prime zone. Card selection can help get either dorks or monsters when needed. Finding out this "general strategy guide" for other archetypes is key.
Hopefully a somewhat coherent glimpse into how I, at least, build up major archetypes. This will start to make pieces of the cube click into place. And it'll highlight areas that might have spells that aren't needed, or where you need more support "wow, Oring has come up like 7 times already" -> add banishing light. Etc. That is, your identities shape archetypes, which feeds back into shaping identities ("My white section is too slow, I want aggro to work in multiple pairs and colors" -> reducing white curve)
And as always, we are all here to help. Come forward with a rough list of overall themes, and we can start bashing out stuff.
