I'm intrigued by some ideas.
Actually, I think drop rates for False Gods are quite good. You need to sweat, but it's not impossible. I got myself 4 Electrum Hourglasses before even coming to the forums, and then I read the expert's advice and modified my original rainbow thanks to their ideas (taking away cards like Trident and Arctic Octopus, which didn't really do any good in the first place and replacing them with some awesome Quintessences). I'm starting to fight the FGs seriously and maybe I'm just lucky, but I don't think the card drops would need THAT much of an increase.
BUT!
You make an interesting point. I did have an extended pause where I was trying to get to FGs and couldn't really pull it off, and found strange that there was no in-between. As far as I know, the best way to get from newbie to FG slayer is through Sacredgirl's Rainbow, which would require like 6000 coins to get the first upgrades in (and gods do they help). Grinding 6000 golds is LAME and more importantly UNEXCITING.
So, I suggest another approach, using your ideas. Do indeed introduce Relics (or something) and make it so that Half-Bloods drop them. Like, a Half-Blood drops 1 Relic, 2 if with Elemental Mastery. Possibly, even FGs drop Relics, but not that necessary.
Then make it so that 30 Relics, or even up to 50 Relics, can get you a random upgraded card. That would make people grind Half-Bloods (which are usually just SKIPPED ALTOGETHER) and make them actually useful for that intermediate step. Then, when you have farmed to some decent levels and have an anti-FG deck ready, you can go and farm the (still more rewarding) False Gods.
I'm not sure if FGs would still be more rewarding after this change, but I'm sure SOMETHING can be done so that AI 5 has a purpose...
I'm liking your idea. AI5 would have a purpose if they dropped relics and to exchange (nn) relics to receive a randomly upgraded card.
In all honesty, I went off and make a variant of CC Why Bother deck, and I'm kicking most Gods butts now. My inaccurately recorded win ratio feels like 85% against everyone except Rainbow and Seism pretty much. Drop rates suck, but I managed to get three cards from False God yesterday.
So maybe the real issue here isn't the drop rates, but a helpful transition that might add a new level of fun to the game which is both helpful to new players and exciting to old players.
Here is another idea that may not took an incredible effort to build. In the upgrade card quest / window, it will say "1,500 electrum or (nn) relics". The game would first check for the sufficient amount of relics and if the user has them, it uses that before electrum.
ALTER TABLE `cards` ADD `relic_cost` INT( 12 ) NULL DEFAULT '30';
To determine how much each card costs for relics, a new column in the database for card entries would be called `relic_cost` - int(12) default "30". From there, you'd manually edit the columns for particular cards which would serve as the "exception". Like Trident, that would cost (40) relics.