On the side of "strengths" for Ralph would have to be his appeal to reason and rationality. Ralph inspects the island at the exposition of the story, and develops the basic premise that organizes life on the island. The use of the conch helps to bolster his claim to leadership and Ralph asserts himself as a leader. His insistence and driven nature to preserve the signal fire as a way to attract attention for rescue, as well as his actions that emphasize organization, and rational values are aspects of his strength qualities. Ralph recognizes and understands leadership. This becomes one of his greatest attributes up to chapter 8.
On the weaknesses side of the ledger would have to be that Ralph acquiesces to the "lesser angels" of his leadership capacity. He is direct when he considers Piggy to be a "bore" as opposed to a voice that must be preserved. Ralph fails to acknowledge the conditions of barbarism that are taking a hold of the island's inhabitants and himself. Ralph's weakness arises in his lack of conviction for the need to preserve and maintain order as its own intrinsic good. His lack of faith and conviction is what enables him to err on the side of the barbaric and savage Jack in moments of weakness. He is unable to control the entropy of his leadership and this becomes a weakness. Ralph's lack of conviction drive him to embrace the mob mentality, as seen in the group beating of Robert. It becomes clear that Ralph is unable to stem the tide of his lack of leadership and his weakness is masqueraded by his own delusion that he can exert control: “By now, Ralph had no self-consciousness in public thinking but would treat the day’s decision as though he were playing chess. The only trouble was that he would never be a very good chess player.” Ralph's lack of skillful understandings, his failures that would prevent him from ever being "a very good chess player," are part of his overall failures in the narrative up to chapter 8.