Hi Agusado,
The issues you bring up have been discussed several times before. Many people have exactly the same issues.
To answer your first question: when newer versions are released, they typically contain features / functionality not covered by a previous version. A good example of this are the Express - VI's. Unfortunately, there is a mechanism that prevents direct backward compatibility because they do not support features that did not exist. Howver, if you do have the "latest & greatest", you can save back one previous version... But that does not help you.
Your suggestion is an excellent one to indicate the version of the vi's. Many of us placed the version we used or have access to in our signatures. However, most people who posted questions did not indicate the versions they used. So unfortunately, although an excellent suggestion, it was not a practicle one.
Your second suggestion is also an excellent one. I think we asked for that somewhere in this forum. We found out that what is described in the first answer is a limitation to have a "version converter".. Maybe it should be one of the "Labview Challenge" projects / contest.
And, yes... getting / purchasing the latest version is an ongoing issue with most people. When your a consultant, it is not as bad because most customers do not have LV and they end up buying the latest one. Having been a manager, it is not easy getting signatures from the VP's and Finance people.
Excellent questions and concerns. I wish I had better answers for you... and myself included 😉
However, if you ask to translate the version of a given vi (example, etc), most people will be more than happy to do it for you.
Have fun wiring,
JLV
😄