secondly, how hard would it be to convert vb6 to vb.net? i understand there are programs to help but how much effort would it be to go back behind the program and tidy things up?
These program are bull****.
EO was written poorly, and its architecture leads you to problem of limitation you may have encounter.
Therefore, if EO is built that bad it is not due to its dev but it is rather because of VB6.
Right now, VB6 is a quite old(it uses COM which is outdated), the needs of users and developpers evolved a lot since VB6.
Converting as it is to VB.Net, it’s possible but you won’t get any advantages…
Firstly, because convert an outdated architecture to a brand new language won’t make the architecture modern and able to host more thant 70, even if the language is “more powerful”.
On the other hand, because programming techniques change, the way of managing data change a lot between languages, even more when you compare VB6 to new langages.
And upgrading the current architecture to a modern one is suicidal undertaking…
If you want to getting started with a new language, you would have to set up a completely new engines, with its own features and its own architecture.
But it would take several years to get something really interesting and to be able to develop your game.
If not, you won’t gain any performance, just by migrating to another language.
However, there are different way in order to improve the perf of EO, you could for instance use C++ DLL to extend the VB6 possibilities or use it for complex algorithm with a lot of calculation(like A* pathfinding), but we could discuss about their long-term sustainability.
Anyway, one day if your project grow up, you would have to move on something new.