That’s a great question! And one I think may have a fairly simple solution, thankfully. Before I propose my fix, I’ll let you know a method that I use to troubleshoot these types of issues, as it definitely gets hard to pinpoint these problems when we are using a lot of modifiers!
What I normally do when I run into an issue is I start hiding my most recent modifiers to see if the problem still persists or not, and if it doesn’t, I know that it was an issue with that specific mod. Where I think you are running into this issue may be in your Array modifier. I think you may need to play around with the offset you are giving to each of your instanced cords, because that is what is giving you the gap. As well, there is a “merge” option within the Array modifier, I would take a look at that as well, as it will merge vertices that are close enough so that your cord is all one continuous mesh.
As for the second question, when you use an operator (basically any action in Blender that does something), you will have that little black box appear in the bottom left of your viewport. That is the “Recent Operator” window, and it will allow you to tweak the last thing you’ve done. So if you manually subdivide your curve (select the edge you want to subdivide, hit W and select “Subdivide”), that window will pop up and allow you to do more or less cuts.
I hope that gives you a solid starting base, and please let me know if you have anymore questions! 🙂
