We have no idea why, but support has recently been bombarded by requests for the limits of various systems in the Iron Engine. Thus, I have taken the time to compile a list of as many as a I could within my breakfast and lunch timeframe. I will add more as requested as this is certainly not comprehensive. I hope it helps 
enum { MaxNumWeaponBanks = 4 };
enum { MAX_NUM_MESHES = 400 };
enum { MAX_NUM_FILE_TEXTURES = 1000 };
enum { MAX_NUM_FILE_CUBE_TEXTURES = 10 };
enum { MAX_SOUNDDATA = 2000 };
enum { MAX_SOUNDIDS_PER_TYPE = 6 };
static const int MAXNUMALTERNATES = 4; //sound alternates
enum { MAX_NUM_ICONS = 2000 };
enum { MaxNumSegments = 20 }; //exhaust trails
enum { MaxNumTrails = 4 }; //exhaust trails
struct MaxNumLinearPathEffects{enum {Value = 1000};};
struct MaxNumBeamEffects{enum {Value = 1000};};
struct MaxNumAttachedWeaponFireEffects{enum {Value = 2000};};
struct MaxNumAttachedWeaponHitEffects{enum {Value = 2000};};
struct MaxNumAttachedWeaponCriticalEffects{enum {Value = 200};};
struct MaxNumAttachedPersistentDamageEffects{enum {Value = 200};};
struct MaxNumAttachedBuffEffects{enum {Value = 1000};};
struct MaxNumAttachedExhaustEffects{enum {Value = 1000};};
struct MaxNumAttachedExplosionEffects{enum {Value = 200};};
struct MaxNumShieldEffects{enum {Value = 1000};};
struct MaxNumMissileEffects{enum {Value = 1000};};
struct MaxNumTrailEffects{enum {Value = 250};};
enum { MAX_NUM_PARTICLES = 6000 };
enum { MAX_NUM_PARTICLE_SIMULATIONS = 2000 };
enum { MAX_NUM_EMITTERS_PER_SIMULATION = 10 };
enum { MAX_NUM_AFFECTORS_PER_SIMULATION = 15 };
enum { MAX_NUM_RESEARCH_TIERS = 8 };
enum { MAX_NUM_RESEARCH_TRACK_SIZE = 8 };
enum { MAX_NUM_BUFF_LEVELS = 3 };
enum { MAX_NUM_EXPERIENCE_LEVELS = 10 };
enum { CapitalShipMaxFlairEffectCount = 10 };
enum { FrigateMaxFlairEffectCount = 10 };
enum { PlanetModuleOrbitMaxFlairEffectCount = 10 };
enum { StarBaseMaxFlairEffectCount = 25 };
enum { CannonShellMaxFlairEffectCount = 1 };
enum { StarMaxFlairEffectCount = 1 };
enum { PlanetMaxFlairEffectCount = 10 };
enum { SpaceMineMaxFlairEffectCount = 1 };
enum {MaxNumWeapons = 3};
enum {MaxWeaponPointCount = 20}; //per weapon per bank (so 3 * 4 * 20 = 240 total)
enum {MaxNumPersistentDamageEffectDefinitions = 6};
enum {MaxBuffEffectMeshPointsPerAttachPoint = 25};
enum {MaxStageCount = 10}; (Starbase Upgrades)
enum {MaxStageCount = 10}; (Planet Upgrades)
enum{MaxNumAbilities = 5};
enum{MaxBombEffectPointCount = 10};
enum{MaxNumBuffInstantActions = 5};
enum{MaxNumBuffPeriodicActions = 2};
enum{MaxMeshNames = 12};
enum{MaxNumSpecificDebris = 2};
enum{MaxNumPersistentDamageEffectsPerDef = 10};
enum{MaxNumSquadTypes = 4};
enum{MaxNumHangarPoints = 10};
enum{MaxSkyboxMeshNames = 10};
enum{MaxNumUpgrades = 9}; //starbase upgrades
enum{MaxSpawnShipsRandomEntityCount = 5};
enum{MaxNormalPlayerCount = 10};
enum{MaxAvailablePlayerColorCount = MaxNormalPlayerCount};
enum{MaxFleetSubjectLevels = 9};
enum{MaxPlanetAsteroidCount = 500};
enum{MaxTextures = 4}; //dust clouds
enum{MaxParticlesPerTexture = 200}; //dust clouds
enum{MaxNumFarStarPointGroups = 3};
enum{MaxNumFarStarPoints = 40};
enum{MaxNumHalos = 10};
enum{MaxNumPlanetElevatorConnections = 5};
enum{MaxNumClusters = 50}; //planet elevators
enum{MaxNumElevators = MaxNumClusters * NumElevatorsPerCluster};
enum{MaxNumStars = 50}; //background stars
enum{MaxNumStarTextures = 10}; //background stars
enum{MaxNumExhaustPoints = 10}; //exhaust trails
enum{MaxNumEffects = 200}; //exhaust trails
enum{MaxNumUniqueTextures = 2}; //exhaust trails
enum{MaxSubExplosionCount = 12};
