Haha... Bro... U worry too much la. Ya... U are right that new wetsuit are a bit more buoyant. But I dun think it can cause serious problem to ur buoyancy, given that it's only 3/2mm. If u are really concern abt this... Just do request for a quick buoyancy check with the DM before descending to make sure u are correctly weighted. Bear in mind that I dun use the term neutrally weight cos u can never maintain neutrally weighted throughout the whole dive.
IMO, do try to rely more on ur breathing technique to control ur buoyancy instead of using weights. Personally I prefer being slightly overweighted to start with, so that I will not be positively buoyant atvthe end of the dive when my tank level drop. Back to ur question, I dun think soaking help with the "breaking in" cos neoprene compresses due to pressure at depths. No pressure, no "breaking in". But like I said, no serious concerns here