I have some ideal adding into simutrans.
1) Add country flag stand with national flag will be fun:) It can also include simutrans logo flag:) If it can present it with gif in simutrans, it will be great:D
2) Adding military like tanks and demolish building will be nice also:) Also it is not as useful as flag stand, I can it can satisfy for fans of military:D If others like trenches or other military set are added, it will be very very great:D
1) Where would a country flag be used? There are currently country specific paksets which may include flags during game loading for example but I can't see where and what role a flag would play in game.
2) Simutrans is a transport game not a military one. Official paksets do not contain references to military activity and although there is nothing stopping people from adding military themed add-ons any extension to the game engine to allow combat would be beyond the scope of the game and as such would be denied.