I'm trying to start my first campaign with multiple player races and I've run into small little hiccup (possible game design flaw?) with the zero RP conventional start. That being when trying to design weaponry and fire controls for combat ships, you run into this problem where you can design and build Beam Fire Controls, but not Beam weapons, as well as the inverse for missiles. I can design and build missiles and launchers, but require Trans-Newtonian and Active Grav Sensor techs to make Missile Fire controls.
As disappointing as it is to forgo pre-TN railguns and lasers that are already in development now, I'm fine with just having missiles as the only available armament. But my actual question is can I actually use missiles without MFC? I know I can add Active/EM/IR sensors to missiles which supposedly are for re-tracking onto lost or new targets, but i haven't really played with them much in the past. If I build these sensors into my missiles is there a way I can launch them in the general direction of a target with out an actual MFC lock and hope that they hit?
You cannot have truly Conventional campaign, for several reasons but the most important is that without researching TN-Theory, you cannot have Active Sensors which are absolutely required for space combat.
I have used some light DB modding on a separate 1.13 DB to add in necessary technologies to allow for a somewhat playable conventional setup without initially researching TN Tech before doing anything. I haven't enabled beam weapons (frankly I think they would be a bit OP since conventional missiles are very limited) but with conventional tiers of the sensor techs you can build the needed sensors and MFCs plus I enable a conventional CIWS for missile defense along with the basic transport modules as researchable tech.
The main limits remaining are lack of targetable beam weapons (even basic Gauss, 10cm Railgun, or Laser would likely overpower un-boosted missiles, so this isn't a big loss) and geosurvey which means you cannot find mineral sources on other planets to mine. To solve the latter would probably require adding a new, inefficient survey component (something like: 500 tons and 0.25 survey points/hour) along with the tech to enable it and I will probably do this at some point.
All this to say... the needed changes are not difficult and can be done DB-only so it would not be much work for Steve, but if he will not do it then it is not a problem for a player with a DB editor to make the changes. Of course doing this means you cannot submit a bug report (or must reproduce with an unmodded DB first which is what I do).
For ground combat, you'll need to use SM mode to create communications between all powers on Earth and set their relations to what you want because you cannot create diplomatic ships either. And ground units cannot fight what they cannot see which brings you back to the sensor problem. Plus, while you can use fighters to move colonists around, there are no cargo holds small enough for fighters.
Actually the diplomatic modules are available without TN tech. You also have access to cargo holds + shuttle bays, luxury transport (but not cryogenics), and the recreational module for all the good that does anyone, so with the starting shipyards it is not difficult to at least colonize Sol but it is pointless to do so without knowing where the minerals are.
Essentially "all" that is needed for conventional starts to be playable are conventional active and geosurvey sensors, with conventional troop transport modules being desirable as well. Once you have this you can at least survey, colonize, mine other bodies, and have missile combat + ground combat, which is the bare minimum needed tor a playable 4X game.