No need to apologize to anyone for the way you choose to play with your toy airplanes :-)

Now, see, you have accomplished something I didn't.  It ignored my speed restriction, which is why I did it the other way.  So that means that the suspected problem in the program is more likely a problem in what I was doing.  If I can't get it right, I'll be asking you for help.

Yes, much better to practice stuff a bit at a time, rather than learn at end of a nine hour flight you don't know how to find your flap settings and vref speed!

You might try saving the flight after you got it all set up.  Whether it will save the panel state perfectly or not, I don't know.  Don't forget you can at least save the route that you have created as a company route.  That might save you some work.

As far as just resetting the FMC, that's a good question.