Thanks again for the replies. Things are becoming clearer now. So basically all I need to keep in mind is that optimization is number one priority. I'm well in the know about C2's limitations and have already cut some elements of my game according to them without hurting the final product. Performance-wise it's good to have a strong graphical style in mind and knowledge of how to keep it as light for the engine as possible. That's something I've finally begun to grasp. I don't even use that many WebGL effects anymore because most of those effects could be done in the graphics themselves.
But without rambling too much, all I can say is that I'm finally beginning to understand what to keep in mind while working on my project. Thanks guys!
I wish I produced a bunch of small games (with finishing touches) before I tackled this larger project I am currently working on. Seeing a game all the way through definitely teaches you something special, and can really help.
It's always best to star with small projects, but finishing them is not always necessary. I've done lots and lots of different test projects over the few years in C2 and learned much about streamlining things and how to make the project easier to control in the grand scale. Making beat em ups and a turn based RPG battle system is a good way to learn C2.