That was actually a great read +
It wouldn't take much to add to SS to make its core combat feel much better. Having the player consider a bunch of dimensions such as spacing and well, frame data of weapons and enemies, isn't necessary. That's the beauty of Monster Hunter's combat, but this stuff can go unnoticed. I think a great deal of the addictiveness from these games doesn't come from it's depth, but rather the random items (skinner box etc.)
But anyway, I think you mostly hit the nail on the head when you said the game has a lot of variety of different spells that don't really do much. The problem here is that you have two kinds of people -- those who want stats to disctate their abilities (my sword does x damage etc, it has x% of certain element), and those who want real time strategic combat to dictate the effectiveness of the character.
SS certainly has this stuff inside, but it has certain elements that for you and me ruin the whole experience.
Let's say for example if Monster Hunter had hyper armour -- by that I mean when you attack (only when attacking) the enemies couldn't interrupt you. Now they can still damage you, but for the most part who cares unless they're going to kill you before you can heal. Suddenly we start to see the game very differently and spacial awareness goes out the window, now we only care about how many hits it takes to drop a monter and how much health we have.
That sounds a bit easy, so as the developer of this broken version of Monter Hunter, let's rank up the difficulty by giving enemies very damaging attacks. This is a bad solution, since while it makes the game *harder*, it creates a new problem where the game feels hard for the wrong reasons. The lack of feedback from getting hit while attacking means now the game has this whole turn-based "I take x hits, he takes y hits" exchange going on. Now you could play it as you would before, but now enemies are very hard hitting, and when they're not, you no longer care about spacing or timing.
The above game doesn't play like SS, but it has a similar issue. Granted I don't know if there are ways to get your HP up effectively, because saving didn't seem to do much, but there we have two groups of enemies regardless. Those we just spam the same attack button until they fall, and those who we wait patiently until they stop attacking so we can get hits in without getting hurt ourselves. The lack of interrupting the enemy means, outside of using range attacks, you're simply waiting for the enemy to let you attack you. The worst example is fighting a bird with just a melee weapon -- it flies around and only after x seconds it does one of two attacks, and you can only use a melee weapon if it flies at you -- miss your chance and you have to wait again.
To be honest I don't think SS needs to abandon its whole "summing weapons and abilities" thing -- I think what it needs to do is play around with them to make them either more unique from each other (and I'm not talking stat wise). Or it could really integrate the whole summoning powers from the environment thing and make it so that you can get weapons from lesser enemies that are strong against the bigger ones. Like say, while fighting the Harpy, we know it's weak to fire (I think) -- make a lesser fire enemy that when saved it gives you HP, and when sacrificed it gives you one shot or hit of a fire weapon.
But alas, this game is clearly heavily reliant on it's RPG/collecting nature overall. I can't comment on it being done right, but this is a game that's compared to MonHan or a Souls game that are really combat first, RPG later.
I don't feel that anything you're saying here rings true at all.
Overall I think the problem is that I want interaction between the AI and how I fight them to the main thing here. If it's not, why bother having so many different kinds of attacks (slow, fast, long-range etc.) -- I won't say SS is a rubbish game, because I'm asking for it to give me something other's don't look for, but it does have an interesting setting. However, the game was marketed to me as having good combat, and it simply does not.
EDIT: Uh, you know, I just did a whole MonHan vs. SS discussion with my friend and well... I just think it's best to say there are people who like the game and people who don't and leave it there. It's like a joke, it becomes lame when you try to explain it.