back to the OP (though i must say the OT was very entertaining).

i agree with PVD on ZRH and MUC - love those airports - a breeze to transit through

a couple of things you want to consider
1) is your mother more comfortable in a non stop 15 / 16 hour flight or prefer a break in between
2) meals - from all otehr accounts it seems like AI will offer better Indian options - on a Eurpean carrier while you will get Indian options on the first leg, you must specifically request special meals for the second leg if your mother is particular

you also asked in AI - seat selection can be done at the time of booking on the AI site (even before making the payment - so in case you dont like available seats, cancel before reaching the payment page)