2) Well, if it doesn't matter which restriction to adopt—then let's adopt the one from the Portal: not using magic against a person until the guild is built (but against monsters it's allowed, and training such specialists is also allowed) (I explained above why I think so, and recently encountered this in a game with Invisiblom, when on day 2 Solmir level 1 came to me with 80 mana and killed half my army, is that normal ??? (and if Solmir had come to me on the 7th day of the game—then he alone could have killed everything)
4) Regarding the ban on the Necromancy booster—I didn't find anything about this in the rules anywhere (although I read about it several times yesterday). But besides that, we also need to forbid choosing the hero; again, I already explained why above: shortly—Galtran starting with full stacks makes a Necromancer even with the same ban on the booster into a cheating, practically invincible castle, which in such a scenario no one would want to play against (if both players more or less know how to play)
Added after 8 minutes
Предлагаю рассмотреть еще один пункт правил:
Если у игрока имеется не менее 2-х одинаковых замков,
то войска выше 3-го уровня разрешается скупать только в первом из замков.
I fully support this, I wanted to suggest the same thing... Otherwise it becomes too powerful when the opponent builds all levels in both castles simultaneously and then combines them ...