Hi, a few comments after reading a few pages (both from the beginning and the end):
1. Effective way for increasing manpower: Have some sort of national service. Brings about 70% of the male population into the reserve force annually, plus the volunteering females (assuming you go with male conscription and female volunteers as quite a few Western nations do/did). Mind you, Russia has a conscription in effect, too... well, atleast sort of. My to-be-announced AU should have a
maximum reserve strength of around 1 million, for a 10 million nation. With an active strength of less than 100k.
When done well enough, the results are very impressive - just look at the Swiss. They got Brigadier Generals in the reserves, and the reserve units conduct their own yearly live-fire exercises. And some months of proper discipline and taking responsibilities hardly should have a negative effect in young men, atleast if they can be kept motivated.
2. For APC - look at some MRAPs and for example
the Czech Tatrapan, based on the very reliable Tatra 815 truck. The also based a proper APC on Tatra trucks, the OT-64 SKOT. Besides other things like SPGs and rocket launchers. Being based on a truck, it shouldn't be very difficult to enlarge the cargo space if needed. And Tatra trucks, well, are just awesome and all that.
3. Continuing with APCs, Sisu Pasi (Patria XA-180 and XA-200 series) and the German TPz Fuchs are bots fairly "peaceful" looking and with plenty of space.
4. Was going to say something here, but my brain is starting to turn itself off, so I'll just leave it be.