Hmm. I wonder if there aren't any other means of succesfully resurrecting (and sustaining) this project. As OPU has existed for a long time, perhaps it's better to accept an OP1 remake won't happen at a steady pace, and that there'll be times when the programmer resource pool dries up completely, only to have some new ones show up some months later...
Don't get me wrong, it's a daunting task to begin with, as the original is so buggy it's hard to get what's going on, not to mention programming techniques and hardware have changed considerably over time, and things that were okay back then could be a big no-no today, and vice versa.
Considering the rather volatile lifecycle of open-source projects, wouldn't it be better to opt for a 'high ceremony, low cycles' approach, making documentation the most important artifact ? Thus setting out the prerequisites at the start, making use of Use Cases, and from those generate a Class Diagram, and only after that's all in place start writing code?
Some of you may recognise the Waterfall model in this approach, while it's bloated and slow, it does offer possibilities to 'restart' with new people as its documentation level is much higher. And it doesn't require anyone to go through code to get what's going on.
Also, this would allow 'roll-backs' of certain parts of the project, e.g. if it should be decided that the engine needed to be updated/changed, or that certain modules are to be added/removed.
In short, I respect croxis' attempt very much, and noone is pointing fingers here, everyone has their own priorities, and noone can expect "recreating a game" to be the first on that list.
In short, if I would ever try to recreate it, it would be as vanilla as vanilla could be, whatever should have been possible in the original, should be possible in its recreation. Mixes with OP2 or other RTS game element are a noble intent, but will almost surely never be implemented and could make the development process even more complicated.
As for the ideas of mixing several game elements into a new one: I really liked how OP1 placed 'Science' first and used 'Science' to generate progress. While I do love certain aspects of OP2, its combat system doesn't make very much sense and makes it look rather cheesy and cartoony IMO. OP1 had a more 'serious' approach, the smallest mistake on your end (and with a little help from the bugs) could cause you to lose it all.
Ofcourse a project is only viable if there are people willing to participate in it!