I have not received a single rare soul (That I can recall) from the above listed amount of play all week. Thus, if I had to guess, it would 'seem' as though the drop rate be 1 every 10 days or so... Disregarding login rewards.
Your first question is not so easy to answer directly. I am unhappy as is because character slots are limited at 100 with no progress to expand and daily rewards requiring open slots to hatch 5 souls daily. I have 96 slots filled, with 2-3 holdouts for sacrifice (I had to dump a good half-dozen or so to accommodate halloween promo characters). So, while 90+ rare souls/week remains little benefit to me ATM, the stockpiling remains necessary for promos and sacrifice if/when it ever happens.
My second issue is that these 'balancing'/limitation patches not only increase the chance for something else to malfunction in the game, but they take time and resources away from fixing what is broken and producing what is promised, and this misguided display of priorities is what really upsets me.