Copyright and what to do

Hi All
as you can all see i am new here and really i am new at the idea of VBA.
i am a WoodWork Teacher in Australia. i teach high school years 8-12 and with more and more of my time being taken up with marking to a Rubric i thought i could save some time and make a excel workbook that stores student grades, has a rubric front page and is editable with some ease so that i could change it for each project i get students to make.
to that end i have produced a teachers mark book that not only does that but more and it has saved my time more than i could imagine. Many of my teacher friends also think it is great and i give it to then saying share as you will. Anyway as i was building this sort of data base i came across this forum and i must say i am very glad i did. i have introduced myself and even put up a question. had a couple of responses from nice people one very nice person. Sadly though no solution. I am now thinking of putting the question onto the commercial forum. but before i do i am not sure about a few things and it will effect my willingness to pay or how much to pay for this.sorry for taking so long to get here.
Q1: if i pay for a solution Who owns it. i have made this rubric for me however people have requested a copy of it. i have and will continue to give it away freely.
Q2:when if i get a solution who owns it.
Q3:is there anyway i can make sure i don't have someone take my free thing and put copyright on it. i know this may only be opinion however i thought people might have gone through it.
Q4: i have brought an Excel addon and when i got it i was surprised to find the code was password protected. i do understand in a way however if i include it in my rubric others would have to pay and that was not my intention.
Q5: sorry final question how much is a fair price. i am a teacher not a banker and while everyone needs to eat i do not want to be the one taking advantage of anyone.

sorry for the protracted post but i really have no understanding of these things.

Really sorry one other question. although i sort of implied it i did not specifically ask. if a soultion is provided and it is password protected do i have to pay as i am looking for something i can give to others.

kind regards
Mark

Q1: You do - You paid, after all. However, if it's a on a public board then it's there for all to see/copy/plagarize and pretend it's theirs...
Q2: See above.
Q3: The 'standard cheap way' to provide proof an idea is yours is to post a registered copy to yourself or your lawyer/solicitor and not open it... that does nothing to stop anyone copying it but it can be used as proof the idea/concept is yours - however, I'm not sure a rubric (in the strictest sense of the word as in a list of instructions) is 'copyrightable' but an excel model with custom code certainly is, just include the text "Copyright © 2017 [Your Name]. All Rights Reserved." and you have a copyright.
Q4: No real question but it seems you bought something you want to re-distribute - contact the original seller as that will be subject to licence restrictions.
Q5: Whatever the market will bear. AU$100,000 to WestPac, AU$0 to a charity - wage earners anything in between
Q6 (Unasked) - if you're serious about this, seek professional advice.

If you are doing something like this, why on earth would you want to do this in Excel? If you are looking for a relatively secure application, Excel is NOT the way to go. Passwords can be broken in a matter minutes. Setting up a Server (Database) and having a user friendly UI is the way to go. And this can all be done on your own PC. Obviously you need to have someone build the application for you, but if it is a relatively simple app, it could be banged out in a week or two and you could have totally control of it and where you use it.

To stop copyright, just don't use a public forum and pay someone for an out of the box solution.