That's a laugh. Lincoln didn't worry about constitutional limitations when he suspended Habeus Corpus, or to the Courts today as they trample the FREE EXCERCISE CLAUSE underfoot.
Then you should read the EP again, and Lincoln's explanation of the Constitutional rational and limitations. You should also read his pleadings with the congressional representatives of the 4 Union slave states (none of them were northern and two of them in fact also had rump Confederate legislatures and Representatives in the Confederate congress) virtually pleading with them to lead the efforts in their states to end slavery.
As to Lincoln's suspension of HC and ignoring Taney's order in the Merryman case, let me say this. Lincoln himself admitted that he "likely" did overstep his authority on suspending HC, but that he did it only to defend the rest of the Constitution in a moment of unpresidented crisis. ("Should I respect this one law while the rest of the Constitution is destroyed?) If he had not acted decisively the capitol city would have been cut off from the rest of the Union, and the United States of America would have likely ended that very day.
Current constitutional experts including Chief Justice Renquist have examined Lincoln's actions in the suspension of the writ and said since Congress was not in session and the crisis was immediate, the mere fact that he used a suspension fully proscribed in Article 1 was not in itself unconstitutional. That is a 20th Century interpretation of course, but it does come from a strict constructionist. My own feeling is that the Framers did not intend Constitutional limitations to inadvertently become the source of its own destruction.
As to ignoring Taney, I'd remind you that there is no requirement in the Constitution for either the Legislative or the Executive branch to automatically submit to any ruling from the judicial branch. Separation of powers. If congress didn't like what he did, they could have impeached him, but no ruling from the bench automatically forces any president to do anything. Ignoring the court can be an impeachable offense, but it is not unconstitutional.
I'd also remind you that when Congress returned for an emergency session in July, they not only affirmed every action Lincoln took from April on, but went well beyond in declaring emergency powers. Lincoln spent much time through the next 4 years restraining many of their more extreme actions.