They are what gives you your principle strength. Eaxh building makes certain units. Ammount of units withall their stats add up. Your bonus to allies (what other ppl see on ur profile, and what u see on theirs) is 1/50 of their max building strength; so max units * all the unit stats / 50 is what u see. Its also shown ~midway down ur profilt (your bonus to allis). This doesnt fluctuate. But ur real strength does as you lose troops (less units)
yessir there are. sorry for misunderstanding your question. the balanced buildings(beastieries or war aviarys) give you 100 extra troops, which means if you dump on an osf you will get two more hits than of you didnt have any balanced buildings you only need one building to get the 2 extra hits, and adding more will not give you more extra. ex: having 24 war aviarys DOESNT give you 48 extra attacks. the defensive buildings( war cathedral, summoning circle) give you +5% plunder, but not on all your plunder, only for THAT BUILDINGS plunder. attack buildings( forge, subtarranean factory) dont give any extra bonuses, nor do tier 1 buildings (barracks, stables, workshop)
No real special effects beastary and avaries have 26 maximum hits, but 5 minutes longer to regen to full (same ratio; simplifies to 2 hits per 5 min) circles and cathedrals make 5% more individually. This means ~10k
Buildings are what get you power, the more expensive, usually the better stats they give you. They also give you max plunder, which is the $ you gain in ATTACKING ONLY from allies. If you have a 259 mil ally, but no builings, you will have no plunder bonus. Read what raeki said over, then mine. That should explain it