1) Yes; it evolves over time. THe limit is not intrinsic to electroid, but from the materials available to hold current and insulate under voltage.
2) Currently yes.
3) THat old favourite, "depends". High altitude gives best visual ranges, and less likely to run into "clouds with rocks", but reconnaisance works better at medium heights, and ground attack at lower ones.
4) This principally applies to turreted guns. Casemated guns on the broadside can typically bear up and down by 60 degrees, and are designed to minimise blind spots. Turreted guns typically elevate by 40-60 degrees, but rarely depress by more than 10-15 degrees. Tactics evolve to handle this - formation flying, and (in fluff terms) rolling the ship can give you a handy fillip of depression to the guns.
5) Sometimes, yes.
6) Perhaps. It's a major difficulty to mount heavy guns in downward-pointing turrets. There are rumours of experiments with fixed-mounted guns pointing straight down, but aiming them would never be easy..
(On a side note, many cruisers - types II and III - have machine-guns which can bear pretty much straight down, and which are often used when 'giving the natives a taste of <insert imperial power> steel'. In game terms, though, these are not worth tracking.)
W.
