Generally no. You may have to appear at certain hearings or conferences (or at a deposition, depending on where you sue) - but normally you can sue in another state without actually travelling there. You will need to find local counsel, however, unless you plan on representing yourself. Additionally, some courts do allow telephonic appearances at certain types of hearings.
Yes
Yes
So one state cannot sue another state.
The state courts
States can sue each other for all reasons. However, in order for states to sue each other, they must go through the Supreme Court.
yes
I/you/we/they sue. He/she/it sues.
Yes, you can sue a person from another state if that person owes you money. Access your local small claims court to file the lawsuit.
Depending on state but this seems very unlikely for any state. In Ohio=NO. They may sue you and seek a judgment for payment and they may present it to unemployment for garnishment but the amount will be a percentage.
They can bring charges from another state. Often the agreement that the debt was incurred under specifies a state to bring charges in.
Yes, if he/she is licensed to practice in your state.
No, asshat, you can't.