AFR white Planeswalker has a tricky ability to make work. Requires drafting into Monk of Open Hand. Might need to consider replacing this planeswalker with one outside set.

2.3 CURVE AND CARD TYPE BALANCE:

Using a desirable retail draft average as a baseline is a reasonable place to start (WotC article on limited mana curve). In 24 non-land cards, a reasonable average is:

0-1cmc: ~3 (13%) = 6.5 cards in a 50 count coloured section
2 cmc: ~7 (29%) = 14.5 cards in a 50 count coloured section
3 cmc: ~6 (25%) = 12.5 cards in a 50 count coloured section
4cmc: ~4 (17%) = 8.5 cards in a 50 count coloured section
5cmc: ~3 (13%) = 6.5 cards in a 50 count coloured section
6cmc+: ~1 (4%) = 2 cards in a 50 count coloured section
Your curves in different colours may look quite different depending on what archetypes you wish to support. For example, if you intend for red to present aggressive options to your drafters, you would need to include a higher ratio of 1-2CMC creatures and spells, and fewer 4+. Or for a green ramp/cheat shell you might reduce 4-5 drops in favour of a few more 6cmc+ cards etc.

It is worth resisting the temptation to stuff your cube full of flashy high CMC cards as they will very rarely be cast without proper support at 1-3CMC!

CARD TYPE BALANCE:

A typical draft deck in retail limited normally contains ~17 creature spells and ~7 non-creature spells. We can use this as a baseline to model the ratio of creature to non-creature spell available in our cubes. 17 creature spells and 7 non-creatures in 24 total nonland cards =

~70% creature
~30% non-creature.
If we want to include nonbasic lands in this equation, I'll assume 3 nonbasics in a deck brings the ratio to this:

~62% creature (~224 in 360)
~26% non-creature (~95 in 360)
~11% nonbasic lands (~41 in 360)
You can tweak the input figures for what you consider to be the average deck composition, but supplying your drafters with a reasonable ratio of creatures/non-creatures/non-basics is definitely worth considering.