If you mean can you call the note due and payable immediately, I don't think so.
Clause 4 gives you the right to call the note due and payable but Clause 9 limits you to the circumstances under which you can call the note due and payable.
In other words, you'd have to wait 90 days from default.
Granted, there appears to be a conflict between 4 and 9, but you provided the contract so a court will construe any ambiguities and conflicts liberally in favor of the borrower and likely rule that Clause 9 modifies Clause 4.
Generally, it's better to sue somebody where they live, work and bank so the local court there would have leverage over the defendant.
Unfortunately, that costs you in travel time and time off from work and you don't get any of that back.
You could, of course, try suing in ND and see how it goes. You might end up with a default judgment that you can transfer and enforce in Texas. However, there is always a chance that the defendant could claim lack of "personal jurisdiction" (google it) and get the ND case dismissed and you'd have to start all over again in a Texas court.

