Mebsuta - The game should end in '48, as far as I know. The faction leader sets the victory conditions, and you should be able to view those of your own faction as a faction member. As for units for different fronts, you'll want an AT brigade (for the Piercing stat) in at least a quarter to a half of your divisions facing the Soviets, because they're traditionally "tank-heavy". If you have ONE AT brigade to provide the Piercing value, Hard Attack is less important against anything but super-hard divisions of HARM/MEC, SHARM, or their ilk in multiplayer. INF and ART are far better against "soft" divisions, and should provide the bulk of your firepower, even against most armor divisions. Depending on manpower, I run either 3xINF+ART or 2xINF+2xART in most of my divisions, with AT replacing one of those brigades in 1-2 divisions per Corps on fronts where I'm likely to face enemy armor.
BloodAsp - Obviously, Pilot and Ground Crew training doctrines are important (the former for the initial fight, and the latter to reorganize before the next one). Note that high Infrastructure in the province with your airfield will increase the repair rate. Intercept doctrine gives a 5% per level boost to air combat during the Intercept mission, which can be fairly important. The one that gives radar impact on combat is only useful if you're fighting in provinces adjacent to one of your radar installations, meaning that it's totally useless on offensive operations, and only useful on defensive operations if you've built radar in the cities or other provinces you're covering. As you pointed out, increasing targeting against bombers or fighters is a matter of choice (they cancel out if you research both), and not worth the trouble in my opinion. The CAS ground attack doctrine affects the Ground Attack mission, no matter what kind of plane does it, so TAC, FTR, INT, STR, and even CAG and NAV can also benefit from it, if you use them to attack ground units. As far as I know, the Tactical Air Command and the equivalents in other air doctrine trees reduces the ORG loss from performing certain missions, which can reduce down time if you're doing repeated missions of that type over time, but boosting ORG and Morale (ORG recovery) would be more important.
You could merge your whole navy into one giant fleet, but the stacking penalties would make it relatively ineffective. Granted, it should still fight well enough to be viable, but far less efficiently per ship than a smaller fleet. You might also run up against a fair amount of "friendly fire" damage. Generally, I field fleets of 2xBB or BC+2xCA+CVL+6CL or 8DD, and have no problem dealing with most non-carrier fleets, or those with a secondary CV/CVL fleet supporting the main action. You don't want to mix full CVs with either BB or BC, because the CV has priority, and the escorts will all drop back to protect the CV, leaving your BBs hanging out to dry on their own and taking 100% of the incoming fire. Escorts normally take a share of the incoming shots, and those shots have a low chance to hit them, but the shots taken on a capital ship have much higher odds of hitting.
BloodAsp - Obviously, Pilot and Ground Crew training doctrines are important (the former for the initial fight, and the latter to reorganize before the next one). Note that high Infrastructure in the province with your airfield will increase the repair rate. Intercept doctrine gives a 5% per level boost to air combat during the Intercept mission, which can be fairly important. The one that gives radar impact on combat is only useful if you're fighting in provinces adjacent to one of your radar installations, meaning that it's totally useless on offensive operations, and only useful on defensive operations if you've built radar in the cities or other provinces you're covering. As you pointed out, increasing targeting against bombers or fighters is a matter of choice (they cancel out if you research both), and not worth the trouble in my opinion. The CAS ground attack doctrine affects the Ground Attack mission, no matter what kind of plane does it, so TAC, FTR, INT, STR, and even CAG and NAV can also benefit from it, if you use them to attack ground units. As far as I know, the Tactical Air Command and the equivalents in other air doctrine trees reduces the ORG loss from performing certain missions, which can reduce down time if you're doing repeated missions of that type over time, but boosting ORG and Morale (ORG recovery) would be more important.
You could merge your whole navy into one giant fleet, but the stacking penalties would make it relatively ineffective. Granted, it should still fight well enough to be viable, but far less efficiently per ship than a smaller fleet. You might also run up against a fair amount of "friendly fire" damage. Generally, I field fleets of 2xBB or BC+2xCA+CVL+6CL or 8DD, and have no problem dealing with most non-carrier fleets, or those with a secondary CV/CVL fleet supporting the main action. You don't want to mix full CVs with either BB or BC, because the CV has priority, and the escorts will all drop back to protect the CV, leaving your BBs hanging out to dry on their own and taking 100% of the incoming fire. Escorts normally take a share of the incoming shots, and those shots have a low chance to hit them, but the shots taken on a capital ship have much higher odds of hitting.
