I'll try to answer them to the best of my abilities
It's a combination of several factors. First of all 10 years have passed since the launch, so CA is fairly disinterested in the old RomeTW engine. Secondly, we use a complex run-time injection method, which is quite difficult to achieve, but it only modifies the code in memory - which is a legal method of decompilation/reverse engineering. And the final reason is that the kids who first started playing RomeTW 10 years ago have grown up and became C++ developers... resulting in the necessary abilities for this to be possible
You needn't worry - of course we've given serious thought into this and our opinion is that the limits must go. If someone wants to create a tiny mod with 3 units of size 1200, then so be it! Performance will definitely suffer, so anyone who creates such a mod also runs that risk. For Macedonian phalanx however, this allows historical 8x8 squares of 256 men, this is why the current limit is 300.
That would definitely be way too much work to fix with reverse engineering. There would be too many concurrency issues to fix. Even if we had the original source code, - which we don't -, it would be a difficult task.
Thanks! I hope we'll get the help and support needed to finish this project.