Menachem, it’s not “various requests” – ths ONLY thing you find chazal advocating is asking for the niftar to daven on your behalf.
As for the maharil and what he does with those gemaros, I’ve had a few thoughts on that. It could be that the maharil holds that we in our time shouldn’t, because we might end up relying on the neisim too much and actually think that they have power.