Is it really God's good pleasure to withhold the help that someone needed? Would someone who stood by and watched a person drown, whom he could have saved, be exonerated if he explained that it was God's good pleasure to do so?

If you are a calvinist you are hyper. No amount of cover up or attempt at double-talk makes you any different.

"The LORD is good to all: and his tender mercies are over all his works." (Psalms 145.9)

"If any man will do [i.e., wills to do] his [God's] will, he shall know of the doctrine, whether it be of God, or whether I speak of myself" (John 7.17). He offered "if any man will" not to a special elect but to the unregenerated multitude and rabbis who would soon crucify Him.

If any man is willing to do-has a mind and desire and inclination to do God's will... God deals with us as moral beings, and not as beasts or stones.