The command does not imply the ability to obey. Does God command, "be ye holy"? Yet, none can do it, but Christ Jesus. Man is unable because of his will--that is true. But thus, unable. He is corrupt to the core, and so, unwilling. The commands are not meaningless. They establish the standard. And so they point to our inability and our need for Christ.
Take the viewpoint that says that God's foreknowledge is based on what he sees, 'down the corridors of time' (to which I don't subscribe, but I use it here to demonstrate that even the proponents of THAT claim, should admit to the logic. If God knew that we all would disobey, yet created anyway, he intended that we disobey. (I'm not saying that he likes it, but that it is a means to an end--redemption.) If he knows that we will all disobey, then how is the command any more invalid than if it was given to autonomous creatures capable of holiness?
By the way, in your references and points, you are mixing categories, again:
There is the command to everyone, which is not salvific. 'Obedience' to that is surface, in those who are at enmity with God--it is not submission. Those are unable to submit, per Romans 8:7,8.
There is the command to everyone, which is salvific. Repent Seek Believe Choose are all impossible to do salvifically, while at enmity with God. As we have already established, they WILL not, and according to Romans 8:7,8, they cannot submit, nor please God. (Note here, too, a caveat. For those elect, these commands are salvific only in that they are in keeping with Christ's righteousness, already applied. It is not their by the will of the redeemed that they are saved.)
There is the command to the born again, to those justified by (through, from) faith. These are finally enabled to obey, yet even they will not obey perfectly, except by Christ's righteousness.
You have included all three categories under one general statement, which is, apparently, to you, axiomatic, but which falls apart under scrutiny. (And no, I don't claim that a person has to know all this correctly in order to be saved. In fact, I thank God for the ignorance of some of those upon whom he has shown mercy and are born again (Romans 9). Their hearts and even their minds (Romans 8) know him, because of the Spirit of God within them (Ephesians 2; 1 Corinthians 2:14).)