At the begining, other factions' fleets were quite large compared to player's. However, you can easily destoryed them when you got more than 4 cruisers or battleships. Is there any ways to increase the fleet size??
Yeah, it's rather like vanilla where you start out small but once you get enough skills and ships you can steamroll most things (though in Exerelin by the time you reach this point it's time to finish the game, so I'm not as concerned as I might be). Anyway, to answer the question:
Patrol fleets: not easily
Invasion/response fleets: not player side for now, but I could make these scale with player level; is that desirable?
I have seen regular ore and rare cost the same.In general things seem to cost the same.There could be some differences in prices to add more variety to the market.
The ore thing sounds like a trade disruption, was there one going on?
I'm not sure it'll actually work for the purpose of increasing price differentials, but I could try making planets more specialized so they're less likely to produce everything they need themselves.