Whoah, cool ideas for the dice issues, Gorkamorka. Maybe I could let players use a Black d12 if they achieve a circumstantial advantage. Though generally speaking, it's probably better overall game design to count all bonuses and penalties using the same scale of plusses and minuses (you don't want the old Wold of Darkness problem where you could adjust difficulty by either changing number of successes or changing target numbers for success ).
You can do some neat things with the profit system by changing the dice type.
If for example you want to make the game harder you just use D12s in stead of D10s. What you have then done is decreased the value of all skills by 1/6th and made players have to spend more resources to make a roll. You basically make them go through rations and ammo faster.
You could also use this to drop static skills completely. Make all skills be a resource to spend like GumShoe and lower the dice type at the same time. D8s for example.
You could even just use a red an black D6 and make skills a spendable resource and we have more or less recreated GumShoe. :-)
About mixing dice.
I like it for a magic system. One sort of magic affects red dice (Say clerics) and another set of magic affects black dice (Say sorcery). So they can buff and de-buff independently of each other and make interesting effects happen in the game. A cleric and a sorcerer together could buff up the fighter to a black D12 and a red D8. That would give you a 2/3 chance of success on an unskilled role and 74% success on a 2 point skill.
You could then have spells change the dice of a particular skill for a particular number of rolls. "Charm person" gives you a RED D6 for a single persuasion roll. "Giant strength" gives you a BLACK D20 for damage only for one encounter.
What other spell could we make with this?
It's also a way to make magic items. the magic sword rolls a D12 for damage (BLACK ?). Or the magic gun rolls a d12 for hit (RED ?) with 10-11-12 being head.