What can you actually do with these spells?
Let's take miracle for now. You can create a plethora of effects and change the miracle into practically any other spell of sufficiently low level, good. Can you do more? I know the spell has a "Low" casting and a "High" casting, with the high entailing a 25.000 gps worth of diamond dust material component, to achieve truly staggering effects. But when is the distinction made, and what exactly can be achieved with the low casting?
If I cast Miracle, can I beseech my god to grant me a citadel on the plains I am currently observing? A Huge stone fortress could feasably be constructed with multiple castings of wall of stone and shape stone, both of which are fairly low level spells, compared to Miracle. Can this be attained without spending the 25k worth of diamond dust, or is the low casting of miracle supposed to emulate only a single casting of a sufficiently low level spell?
There are spells that lower saves, spells that do not allow spell resistance and spells that allow no save. Could I cast Miracle and beseech my god to cripple my enemy's fortitude save, thereby emulating the effect of a bestow curse, but with no save and no SR, so I can follow it up with a good save or suck spell? Or am I again into high-casting territory?
clarification and reasoning very much appreciated.
Thanks in advance
or is the low casting of miracle supposed to emulate only a single casting of a sufficiently low level spell?
I think you hit the nail on the head here. You could use miracle to do these things as you could with the low level spell, but not in a single casting. In general you could try to imagine the spell effect you are trying to achieve. Wall of Stone may be a 5th/6th level spell, but Create Citadel would certainly be a 9th level spell if it existed. Therefore it's out of the range of a "free" miracle.
Could I cast Miracle and beseech my god to cripple my enemy's fortitude save, thereby emulating the effect of a bestow curse, but with no save and no SR, so I can follow it up with a good save or suck spell?
There is actually a bit about this in the description for Miracle:
A duplicated spell allows saving throws and spell resistance as normal, but the save DCs are as for a 9th-level spell.
So you could get them to make a saving throw as if the spell were 9th level, but you couldn't bypass their save/SR.
They are specifically vague with only general guidelines.
It's an appeal to the God(s) [the GM], or the Universe [the GM], if you try and use them for anything not explicitly spelled out.
They're holdouts from a time, pre video games ;) , when the GM was > Rules in more than just a footnote hidden in the book. :)
You could ask your GM to treat the spell not only as Level 9, but as if it had some metamagic.
[Example: Miracle. Says L8 of Cleric spells is normal, L7 any other. So, Bestow Curse is a 3rd level cleric spell, and the general guidelines of Miracle want you to stay below L8. Persistent spell and Piercing spell would make it a level 6 spell slot. Add in a 2 "level" tax for doing something outside the predefined rules of the spell(1) and because you're getting it combod with Miracles 'spell level 9 for saves' [which is essentially heighten spell, and should really make it a L9 spell... fairer might be to say "and unlike most miracle spells, i's treated as 8 not 9 for save DC] (1), and you've now got a bestow curse saved as if it was level 9 (or 8, if youe being fair) with +5 vs SR and reroll successful saves, and it's in the vague range the spell allows as it's the equiv. of a L8 Cleric spell.]
HOWEVER that variety is POWERFUL and SITUATIONAL. Each and every GM has to make the call of if what's being done is balanced, given these spells are so high they were never really meant for PCs to have casually. (They, by their nature, break the game and all but define "Tier 1" power)
Two additional warnings... 1) If you have to ask what those spells do, really consider as a player or GM if you're ready for them. Reasons exist most players (and PFS) don't like those levels. Level 70 in WoW was fun because growth was mostly linear. Level 20 in PF can be broken because growth is exponential for Tier 1-3 (over half of) classes. 2) Don't allow them if there's any conflict within the gaming table (if pvp is allowed, or any players are known for giving the GM grief on rulings).
That's more advice than rules, but with those spells they need more advice than rules.
Otherwise, good luck and enjoy toying with being a god.