So the player would circumvent the obstacle... differently, I have no issue with that (with the possible exception of it being automatically successful). I might be missing the point here. Would this "As if it wasn't there..." card have any of the limitations a spell might, like not working in an anti-magic field, failling if it doesn't overcome SR or on a successful save, perhaps not being taken because a different power was chosen, and so on? Because as it stands it seems way more powerful than any spell.
You'd have to hammer it into shape with a modicum of specificity, of course, and take into consideration the various interactions with subsystems and general system assumptions. You'd also have to figure out the how the resources are scheduled/rationed (eg 1/day or what). It was just a quick and dirty example of the general principle.
However, way more powerful than any spell? Ghost Sound? Silent Image? The combo of the the two? Charm Person? Spider Climb? Invisibility? Levitation? Any number of these are extraordinarily functional in Exploration encounters where you need to bypass a manned obstacle without conflict. None of these even touch on the ridiculous potency of Sleep, Glitterdust, Empowered Ray of Enfeeblement, Grease as these are of primary use in combat resolution and all encounter-enders of the SoS variety at low level (which isn't relevant to bypassing obstacles, of course...well its relevant to bypassing sentient obstacles).
As too the authorial rights... I'm of a mixed mind on this. Magic doesn't give full authorial control as you are presenting it in number 2, spells have specific rules and limitations surrounding them, but what you are proposing doesn't. I'm also not sure all players should be allowed this type of freedom since it has no boundaries or limitations and there will be players who use that to push the game in a direction that may be fun for them but not necessarily for the DM or even the other players at the table.
Magic gives an extraordinary amount of fiat. Allowing players to contrive the narrative around their spell is more on the technique level than the system level. I routinely let my players do it. They have my trust. Just as I have theirs.
Sure, not all players have the practice in this so they "can't be trusted" (yet). And some might try to push the game in a direction that requires some reining in or table/GM veto. However, the gate swings both ways here. There are untrustworthy GMs, out of practice (or unpracticed) GMs the same as players. I don't know why we should endorse "rulings not rules" design ethos (that implicitly trust the GM) while forbidding player authorial control options (which implicitly distrusts players) when there are plenty of each group lacking the chops and plenty possessing them. I would likely trust most people on this board with authorial control options.
Have you tried using the combat maneuvers in Pathfinder? They have been upgraded alot.
I've GMed a truly absurd amount of 3.x. I've read the Pathfinder changes through and through. Some of them are quite good. However, at the heart of the problem with melee options/disparity between casters and mundane melees is the action economy. The nature of the Full Attack option basically mandates its use progressively as you level. Spending a move actually becomes progressively more and more punitive toward output. Dirty Trick, Drag, Reposition, Overrun options as a Standard Action is just not remotely worth the loss of iterative attacks. To compound the issue, they require a check and feat investment to even get off the ground (eg avoid an AoO). Full Attack and 5 foot move is almost always universally the best option for you personally and for your group and Trip is still your best control.
What a melee character really needs are automatic control and survivability buff riders to basic attacks (or riders that pass their fortune resolution at an extremely high rate). This is why you see trip builds as the go-to for melee. PF tried this with a few of the melee control options but they are again deficient (I wrote a long post somewhere on this outlining the problems with the Defender line of feats) and they require an extreme amount of feat investment (basically your full assemblage) for this net deficiency. Combat Patrol is a very good effort. However, it needed more bite and not such a loss of Action Economy for the melee Defender.
I hacked my game to remove Full Attack and make FA a Standard Action, normalizing the Acton Economy. It had so many 2nd order interaction issues, however, that the whole thing just became too burdensome after awhile.
While I can see where that comes from, it is important to note that without the right spells memorized, the wizard is often fairly useless. At any one time, the wizard is not anywhere near as versatile as you're suggesting; memorizing enough spells to be capable at combat pretty much consumes all the wizard's spells. The wizard's usefulness depends greatly on whether he knows what is coming or has time to prepare and can memorize the right spells in advance (which is probably why my players don't like them; they have no idea most of the time). I tend to look at a fighter as being a bird in hand and a wizard as being two in a bush.
To be fair, once you get into double-digit levels, spell slots aren't much of a limitation anymore. And I still think some limitations on that power are in order. But in actual play, a wizard is more of a C student who can get an A in one course if he tries hard enough.
I wish I still had that post. I broke out so much in there.
Honestly, I just don't see this here.
1e before 9th level...ok, maybe. After that, forget about it.
2e with specializing (which still lets you be a Generalist, Batman Wizard)...by level 5 you're a monster who "should", if you have a reasonable modicum of system mastery) be handling every conflict that arises and by level 9, dominating all theaters of conflict...without any threat of being spell-starved. 3 SoS spells/day memorized and you can Batman your entire spell-load out with all the tricks in the book.
3.x? Scribe Scroll at 1, CWI 3rd, CW 5th? I've never, ever heard of a spell-starved Generalist Wizard in 3.x. I've GMed 6 Wizard players ranging from average system mastery to Magic The Gathering savant level of system mastery. By 5th level, they were spell-factories and dominated all theaters of conflict resolution. Mind you, none of these guys were/are gross, power-gaming jerks (most of them were swell enough folks). They were just playing RaW, core material...not god-awful abominations. In the same time I GMed a few Clerics, Druids and mundane, martial characters. The 3e Druid player was probably worse. Most of my frustration during that period was trying to keep the spirits up of the players of those mundane, martial characters...desperately trying to keep them involved without willfully (in a truly contrived fashion) C-blocking the caster players...and trying to deal with ridiculous Divinations destroying every possible reveal, every investigatory conflict.
However, as I've read aplenty, this all may be because I'm a bad GM and/or my players are (were) entitled.