In the Name of Alah the One and The only
My Dear Brother God bless you
Congratulations for your allegiance & well come among your brothers and sisters
about the blood transfer you were right the body doesn't need any blood transfer it can regenerate blood by itself ,but in some cases specially when body loss too much blood then the transfer become very necessary or else the patient will have a heart fail and die
now the answer for your question my dear is that the Verse forbidden drinking blood not transfer it & also forbidden eating dead anmils & pig meat & any animal Slaughter with out mentioning Allah's name on it only if you was in no were like desert and have nothing else to eat then know that Allah is merciful
you also mention organs transfer you also were right about every thing you said and you understand what Al Imam said perfectly
if you have any more question don't hesitate to ask
Pace be with you my brother