I would rather bid 6♥ than splinter but given the splinter you cannot pass 4♥. I suspect if you ran a simul with the South hand unchanging while giving North an opening 1♥ hand slam will make 6 well over 50% of the time.
in 1)psyches are allowed if you want the opps to help you find it. Of course partner will assume your side has it so it is not risk free. In 2) this is common expert practice but assumes you have the K. The odds of not picking up the Q are so low that it is ignored.
you are asking in a vacuum. What meanings have you assigned to 2m, 2♠, 3m,3♠. Personally I would take as a hand too good to overcall 1♠but with either no ♥ fit or 3 at best.
The argument for 3♣ in all cases is that a)they have a fit so you rate to have one also :( you get the lead you probably want against 3NT needless to say this is not risk free but at least you have a license to steal. :rolleyes:
why wouldn't I want to make a passive lead on this auction. i.e. lead a trump since they are picking up the suit anyway. Next choice would be a ♥. Next would be a minor suit after you pry one out of my cold dead fingers :lol: