How one can dovetail desires for knowledge and renunciation in Krishna consciousness?
Actually, Krishna Consciousness is based on the Vedas. Veda literally means "knowledge," so there should be no problem in dovetailing one's desire for knowledge.
There are two types of knowledge; that which deals exclusively with mundane things, and that which deals with the relationship between the material word, the spiritual energy and the spirit soul (you and I). Mundane knowledge can be dovetailed by using the results of that knowledge in the service of Krishna, and the other knowledge can be used to extricate yourself from the cycle of repeated birth and death. And within the Vedic literature there's knowledge about politics, military science, medicine, agriculture, drama etc.; practically everything can be seen in relationship to Lord Krishna, far more than one can know in one lifetime.
As far as the propensity for renunciation; that is also easily "dovetailable." Real renunciation is described in the Bhagavad-gita chapter 6, verse 1:
"The Supreme Personality of Godhead said: 'One who is unattached to the fruits of his work and who works as he is obligated is in the renounced order of life, and he is the true mystic, not he who lights no fire and performs no duty.'"
We often think of renunciation as "giving up" something - living in poverty, or walking rather than driving a car – however, since nothing is ours in the first place (it all belongs to Krishna!), what can we renounce? We may walk into a bank and shout, "I renounce all the money in this bank!" But since the money isn't ours in the first place, it's a crazy declaration to make. Therefore, Lord Krishna describes renunciation as above: doing one's duty without being attached to the results, giving the results to Krishna. This is true sannyas, or renunciation.
Both rejection of something and attachment to something are signs of personal desire. We want to avoid those things which give us pain or discomfort and get those things which we perceive as giving us happiness. Or perhaps we want to appear renounced or wealthy, so that we can gain fame or adoration. All these motivations are selfish. A true renunciate will see pebbles and gold, friends and enemies, as the same...neither hating nor desiring anything...but simply doing one's duty to the best of his/her ability, and allowing the Lord to do His will in terms of awarding or withholding the result.
I hope that this is helpful.