GenNikolaj wrote:
1) Which difficulty level is the one giving the "true" Pike and Shot experience, and how does it scale - by improving the enemy unit's stats, or does it just increase their unit pool?
The middle three difficulty levels are usually achieved by varying the player's unit pool, although in some scenarios different methods are use, to reflect the historical situation - e.g. in some historical scenarios where the historical forces on the player side were demoralised, the different levels vary the degree of demoralisation. (e.g. White Mountain, Lutter). The lowest difficulty level uses the same forces as the next level up, but troop quality is tweaked slightly - player troops upwards, AI troops downwards. The highest level uses the same forces as the next level down, but AI troops quality is tweaked slightly upwards and player too quality slightly downwards. This can be seen in the unit info panels at the bottom of the battle screen.
All of the levels should give the "true" Pike and Shot experience with regard to the interaction between different unit types and capabilities. We would suggest playing at one of the two lowest levels at first.
2) Are the historical scenarios listed by difficulty? I notice that while individual scenarios within an era are listed chronologically, the eras themselves are not. If some are easier, and some harder - which ones?
The scenarios are organised purely chronologically within the eras. None of them are intended to be easier than others, with the exception of Stratton (ECW) and Pilgram-Lomnitz (TYW).
The game does not force you to play the scenarios in any particular order, you can dip in wherever you like.
Rocroi (TYW), although large, is somewhat easier than many of the others.
Seminara, the first Italian Wars scenario, is particularly hard - historically it was a walkover for the French. Probably best to leave that one until you are more experienced.
Tercio to Salvo was a dlc, designed after the initial release, and its scenarios were designed to be slightly easier than the scenarios in the original release of the game.
We recommend, however, that you cut your teeth on skirmishes before playing the historical scenarios. The historical scenarios were designed to be harder than skimishes, to give them replay value.
3) Are the army lists balanced in terms of gamplay, or are they true to historical reality?
They are designed to be true to historical reality. The points system redresses most imbalances, as the higher the quality of the troops the less you get of them, but there are some matchups which are harder than others.
To keep the game "real", the points system is based more on the cost of fielding a unit, rather than pure game balance. Some of the larger early units are therefore less cost effective than later smaller ones, as they tie up more men in a stronger but less efficient package. Of course, the later units tend to be more fragile, but will outnumber the earlier armies in numbers of units, and thus have greater total firepower.
Thus the points system intentionally does not completely balance out the effects of obsolescence, as more up-to-date unit organisations are often slightly more cost effective than earlier ones, as they were historically. It would be a travesty if the early armies were consistently better than later ones.
Also - any tips from veteran player will be well received, I can't be the only one with a rough start

Take a look at how some people beat various historical scenarios here:
http://www.slitherine.com/forum/viewforum.php?f=320