I blew my vitara build from over heating the oil and needed to put a compromise engine together to get me by.Cool info! I had no clue of the Z1 and B7 cranks being almost the same. Well in that aspect it would seem to me that your second choice of attack is the best for my " Budget minded fun build " safeguarding the bottom end for 250 whp It's too bad they're not like the jdm d15b crank.
"I might just use the leftover OEM's from the Z6 block for my D15Z6HNM on those D15a2 rod's you suggested of course after they receive some TLC." If you can find a machine shop willing to press off the stock pistons without breaking them, more power too you. My local shops won't do it.
"If you dont mind my asking , what was needed to have done to the D15a2 rods in order to make them work on the B7 crank?" Nothing really needed except for different pistons. And you can still find these old civics in junk yards because no one wants the engines in them. D15a2-a3
"so in theory the downfall of me throwing together the D15a2 rods + D16Z6 piston's while using the Z1 cam + ECU & o2 would make for a very unhealthy motor????" R/s Ratio I don't know if ok or not, quench-slightly worse, compression-better than you have now but similar. A little stronger hopefully than z1 tooth pic rods.
"Maybe when i finish building the Mini LS Vtec i'll just pull the D15Z6HNM out as is & keep it in the garage so i can say i have a extra running Hybrid Nitrous/Boost Motor laying around."
From my example, it would be good idea to keep a spare engine ready to go when you start modding like this when running nos or boosting, just in case.