In doing so = in that = in which

1.He enjoys having a soft drink and French fries at almost every meal. In doing so, he is putting his health at risk.
2.He enjoys having a soft drink and French fries at almost every meal, in which he is putting his health at risk.
3.He enjoys having a soft drink and French fries at almost every meal. In that, he is putting his health at risk.

Q1) Are three sentences all correct?
Q2) In #2, is "which" referring to "He enjoys...every meal", and In #3, is "that" referring to "He enjoys...every meal" ?

Q3) If #2 and #3 are not good examples, could there be natural sentences where "in which" and "in that" is fine to use when "which" and "that" are referring to their entire preceding clause? If you cannot think up any natural sentences, could you please answer about whether to use "in which" and "in that" like in #2 and #3 is theoretically possible?