No, not really. Fort Sumter came about only upon the confederates learning that Lincoln had dispatched a fleet of warships to fight their way into charleston harbor and reprovision Sumter. Lincoln's expedition was a recognized act of hostility in the southern minds and was warned against as a hostile act even by members of Lincoln's own cabinet.
They stole weapons from federal arsenals.
They seized arsenals within their own borders and did so several months after offering repeatedly, including on the floor of congress, to provide payments for those and other federal properties in the south as a means of securing a peaceful separation. The yankees would have none of it and Lincoln refused to even meet with the confederate representatives who came to negotiate that separation.
They fired on Ft Sumpter.
That they did. And it was a preemptive strike on the fort for the purpose of minimizing casualties and preventing a larger battle when Lincoln's fleet of warships arrived the next day.
They deserved everything that Lincoln could have given them. And more.
That is an illogical non-sequitur. To suggest that the act of firing upon a single fort in a single state without any casualties incurred justifies the unleashing of a full scale military invasion of that said state plus six others that affiliate with it, five others that had not at the time of the attack affiliated with it, and two more that decided against formally affiliating with it is absurd. It is no more reasonable or deserving than the use of a howitzer to quell a barking dog. Yet that is exactly what Lincoln did.
They had signed no oath to break the Union
Yet they signed many oaths to preserve, protect, and defend their states and homes.
wheras Lincoln had sworn to preserve and protect the Contitution.
Evidently that oath was of little value to Lincoln seeing as he violated the constitution and bill of rights regularly in his waging of the war.
Part of that Constitution was the guarantee of republican government to the states.
Indeed it was and Lincoln violated that guarantee in several cases. The most notable was the rightfully elected state government of Missouri. Even though it was not planning on seceding, Lincoln had it chased out of the state capitol by the army and installed them as his own by force.
That guarantee was meaningless if any state could leave, and then set up its own monarchy or tyranny.
No it isn't when those states that leave show all reason to believe that they are continuing a republican form of government and especially when their decision to leave is itself an act carried out by way of that very same republican form of government. To deny a republican government its ability to govern in a republican form is an immeasurably greater violation of that clause than the simple unfounded fear that a seceding state would adopt some other form of government despite no indication ever being given that they would do so.
It should also be noted that the United States was already a perpetual union before the current Constitution. A state leaving the Union was not only in violation of the Constitution, it was in violation of the Articles of Confederation.
The Articles of Confederation were replaced in 1787, thus ending both their system of government and their professed perpetuity.
When Texas joined the Union, its debts were accepted by the US, and that was a liability given to the other states for the sole benefit of Texicans.
And when Texas joined the union, the union also recieved vast territorial tracts to the north and west of the state including sizable portions of what are now New Mexico, Colorado, and Oklahoma. So they both recieved something from the deal. Is this of consequence upon Texas' status as a state and does it make Texas either subordinate to or superior to the other states? Absolutely not, as the Constitution makes zero distinction between the rights of the original 13 and the rights of those after them.
Lincoln was no more responsible for Roosevelt and Johnson than he was for the man in the moon.
Lincoln was responsible for their ability to exercise vast federal power upon his precedent. With that power they enacted massive federal programs. Thus, while Lincoln himself did not act for either Roosevelt or Johnson, his actions did facilitate their later actions that were built upon what Lincoln did. For that Lincoln deserves a degree of blame for the other two, though no less or more than is applicable upon the concept of precedent.