We're not focused on CH2 at all, if this is a bit of a flop there may not even be one, it's costing me personally close to $300 per month in regular outgoings on interest and host services. Still cheap in development terms. But I think of it as a longer term investment as it's about developing core systems that can be used in the future.
We have talked about what things we want to do differently, a roadmap of sorts, expansions and the next project beyond Combat-Helo. We're always limited by what we can do using off-the-shelf technologies, but we're stuck using it due to costs and time-scale. We want this done as quickly as possible as frankly I'm itching to play the finished game before the debt collectors come around

Personally I'm confident that it'll be a sleeper hit, certainly when we get in the expansion aircraft and a new theater to play in. Tools to help build the maps are something we need to work on later but we have a good idea on how to import veg-data now.
Building a retro-esque game is one thing, but you can't keep doing that as expectations are frankly at the point where games are unsustainable except by the super-rich publishers. But I like to think that simulation enthusiasts are less shallow than your typical gamer and will play something that is fun, challenging and assumes they are intelligent.
Modability ideally needs to be built-in and that consumes time, and there are license/legal considerations. That's something that we can't address properly this time around. But eventually I want to improve the vehicle system and include some kind of SDK, probably LUA based to enable third-parties to go into gauge level detail. But again that's way way off in the future. So let's not get sidetracked by sequels until we have a finished game we can take forward to the next level.